diff --git a/components/calendar/form/Create.vue b/components/calendar/form/Create.vue
index f609d7e..16e0df2 100644
--- a/components/calendar/form/Create.vue
+++ b/components/calendar/form/Create.vue
@@ -1,9 +1,9 @@
 <script lang="ts" setup>
 import type { Calendar } from '~/models/CalendarConfig';
 
-import { PhAlarm, PhCalendarBlank, PhCalendarDots, PhLeaf, PhWrench } from '@phosphor-icons/vue';
+import { PhAlarm, PhCalendarDots, PhWrench } from '@phosphor-icons/vue';
 
-const defaultSkeleton: Calendar = { name: '', today: { day: 1, month: 1, year: 0 }, months: [], events: []}
+const defaultSkeleton: Calendar = { name: '', today: { day: 1, month: 0, year: 0 }, months: [], events: []}
 
 const calendarSkeleton = ref<Calendar>({ ...defaultSkeleton })
 
@@ -16,7 +16,7 @@ onMounted(() => {
 })
 
 type FormTabs = 'global' | 'months' | 'today' | 'seasons'
-const activeTab = ref<FormTabs>('months')
+const activeTab = ref<FormTabs>('global')
 
 /**
  * === Months list handling ===
@@ -25,16 +25,37 @@ const activeTab = ref<FormTabs>('months')
 /**
  * === Current date ===
  */
-function setTodayMonth(e: string) {
-  calendarSkeleton.value.today.month = e
-}
+// If the months data change, just reset today's month
+// This is a failsafe mainly because of 1) month positions and 2) month names
+watch(calendarSkeleton.value.months, () => {
+  calendarSkeleton.value.today.month = 0
+}, { deep: true })
+
+/**
+ * === Form Validation ===
+ */
+
+/**
+ * Whether the skeleton has valid month data
+ */
+const validSkeletonMonths = computed(() => calendarSkeleton.value.months.length > 0)
+
+/**
+ * Whether the skeleton has a valid name
+ */
+const validSkeletonGeneral = computed(() => calendarSkeleton.value.name)
+
+/**
+ * Whether all the data checks above are a-ok
+ */
+const validSkeleton = computed(() => validSkeletonGeneral.value && validSkeletonMonths.value)
 </script>
 
 <template>
   <template v-if="calendarSkeleton">
-    <form class="h-full grid grid-rows-[auto_1fr_auto]" @submit.prevent="handleSubmit">
+    <form class="h-full grid grid-rows-[1fr_auto]" @submit.prevent="handleSubmit">
       <UiTabs v-model:model-value="activeTab">
-        <UiTabsList class="grid w-full grid-cols-4">
+        <UiTabsList class="grid w-full grid-cols-3 mb-4">
           <UiTabsTrigger value="global" class="font-bold">
             <div class="flex items-center gap-1">
               <PhWrench size="18" weight="fill" />
@@ -53,12 +74,12 @@ function setTodayMonth(e: string) {
               Aujourd'hui
             </div>
           </UiTabsTrigger>
-          <UiTabsTrigger value="seasons" class="font-bold">
+          <!-- <UiTabsTrigger value="seasons" class="font-bold">
             <div class="flex items-center gap-1">
               <PhLeaf size="18" weight="fill" />
               Saisons
             </div>
-          </UiTabsTrigger>
+          </UiTabsTrigger> -->
         </UiTabsList>
         <UiTabsContent value="global">
           <input
@@ -68,58 +89,20 @@ function setTodayMonth(e: string) {
             name="new-calendar-name"
             required
             placeholder="Titre"
-            class="w-full -my-1 py-1 -mx-1 px-1 text-lg border-b-[1px] bg-transparent focus-visible:outline-none focus-visible:border-blue-600"
+            class="w-full -my-1 py-2 -mx-1 px-1 text-xl border-b-[1px] bg-transparent focus-visible:outline-none focus-visible:border-blue-600"
           >
         </UiTabsContent>
         <UiTabsContent value="months">
-          <p class="text-lg mb-2 font-semibold">Liste des mois disponibles</p>
-
           <CalendarInputMonthList v-model:model-value="calendarSkeleton.months" />
         </UiTabsContent>
         <UiTabsContent value="today">
-          <p class="text-lg mb-2 font-semibold">Date d'aujourd'hui</p>
-
-          <div class="grid grid-cols-12 gap-2">
-            <div class="col-span-2">
-              <UiInput id="new-month-current-day" v-model="calendarSkeleton.today.day" type="number" name="newMonthCurrentDay" placeholder="Jour" min="1" step="1" class="invalid:border-red-600" />
-            </div>
-            <div class="col-span-4">
-              <UiDropdownMenu>
-                <UiDropdownMenuTrigger as-child :disabled="calendarSkeleton.months.length < 1">
-                  <UiButton size="sm" variant="secondary" class="w-full h-full">
-                    <PhCalendarBlank size="18" weight="fill" />
-
-                    <template v-if="calendarSkeleton.months.length < 1">
-                      Aucun mois disponible
-                    </template>
-                    <template v-else>
-                      Choisir le mois
-                    </template>
-                  </UiButton>
-                </UiDropdownMenuTrigger>
-                <UiDropdownMenuContent :side="'bottom'" :collision-padding="30">
-                  <UiDropdownMenuLabel>Mois disponibles</UiDropdownMenuLabel>
-                  <UiDropdownMenuSeparator />
-                  <UiDropdownMenuItem
-                    v-for="m in calendarSkeleton.months"
-                    :key="m.name"
-                    @click="setTodayMonth(m.name)"
-                  >
-                    {{ m.name }}
-                  </UiDropdownMenuItem>
-                </UiDropdownMenuContent>
-              </UiDropdownMenu>
-            </div>
-            <div class="col-span-2">
-              <UiInput id="new-month-current-day" v-model="calendarSkeleton.today.year" type="number" name="newMonthCurrentYear" placeholder="Année" step="1" class="invalid:border-red-600" />
-            </div>
-          </div>
+          <CalendarInputTodaySelect v-model:model-value="calendarSkeleton.today" :available-months="calendarSkeleton.months"/>
         </UiTabsContent>
         <UiTabsContent value="seasons" />
       </UiTabs>
 
       <footer class="text-right mt-6">
-        <UiButton type="submit">
+        <UiButton type="submit" :disabled="!validSkeleton">
           Créer
         </UiButton>
       </footer>
diff --git a/components/calendar/input/MonthList.vue b/components/calendar/input/MonthList.vue
index d8a3fea..a82c86b 100644
--- a/components/calendar/input/MonthList.vue
+++ b/components/calendar/input/MonthList.vue
@@ -1,10 +1,13 @@
 <script lang="ts" setup>
+import { cn } from '~/lib/utils';
+
 import { useSortable } from '@vueuse/integrations/useSortable';
 import type { CalendarMonth } from '~/models/CalendarMonth';
 
 import { PhList, PhPlus, PhTrash } from '@phosphor-icons/vue';
 
 const model = defineModel<CalendarMonth[]>({ required: true })
+
 /**
  * Input value for new month's name
  */
@@ -12,7 +15,8 @@ const monthName: Ref<string | undefined> = ref<string>()
 const monthNameRef = ref<HTMLInputElement>()
 const { focused: monthNameFocused } = useFocus(monthNameRef)
 const validMonthNameDatatypes = ['string']
-const validMonthName = computed(() => validMonthNameDatatypes.includes(typeof monthName.value))
+const monthNameIsTaken = computed(() => model.value.find(m => m.name === monthName.value))
+const validMonthName = computed(() => validMonthNameDatatypes.includes(typeof monthName.value) && !monthNameIsTaken.value)
 
 /**
  * Input value for new month's number of days
@@ -20,14 +24,17 @@ const validMonthName = computed(() => validMonthNameDatatypes.includes(typeof mo
 const monthDays: Ref<number | undefined> = ref<number>()
 const monthDaysRef = ref<HTMLInputElement>()
 const validMonthDaysDatatypes = ['number']
-const validMonthDays = computed(() => validMonthDaysDatatypes.includes(typeof monthDays.value))
+const validMonthDays = computed(() => validMonthDaysDatatypes.includes(typeof monthDays.value) && monthDays.value && monthDays.value >= 12)
 
 const validNewMonth = computed(() => validMonthDays.value && validMonthName.value)
 
-function addMonthToCalendar() {
-  console.log(monthDays.value, monthName.value)
+/**
+ * Add current month input data to the model list
+ */
+function addMonthToModel(): void {
   if (!monthDays.value || !monthName.value) return
 
+  // Create month object to add
   const monthToInsert: CalendarMonth = {
     name: monthName.value,
     days: monthDays.value,
@@ -36,81 +43,92 @@ function addMonthToCalendar() {
 
   model.value.push(monthToInsert)
 
+  // Reset form state
   monthName.value = ''
   monthNameFocused.value = true
 }
 
-function removeMonthFromCalendar(index: number) {
+/**
+ * Remove a specific month from the model
+ *
+ * @param index Index position of the month in the model
+ */
+function removeMonthFromModel(index: number) {
   if (isNaN(index)) return
 
   model.value.splice(index, 1)
 }
 
-// Sortable
+// Sortable setup
 const monthSortableList = ref<HTMLElement | null>(null)
-useSortable(monthSortableList, model.value, { animation: 150 })
+useSortable(monthSortableList, model.value, { animation: 150, handle: ".handle" })
 </script>
 
 <template>
   <div class="grid md:grid-cols-12 gap-4 items-center">
     <div class="md:col-start-2 md:col-span-5">
-      <UiInput id="new-month-name" ref="monthNameRef" v-model="monthName" type="text" name="newMonthName" placeholder="Nom du mois" />
+      <UiInput id="new-month-name" ref="monthNameRef" v-model="monthName" type="text" name="newMonthName" placeholder="Nom du mois" :class="cn({ 'border-red-600': monthNameIsTaken })"/>
     </div>
     <div class="md:col-span-5">
       <UiInput id="new-month-days" ref="monthDaysRef" v-model="monthDays" type="number" name="newMonthName" placeholder="Nombre de jours" min="0" step="1" class="invalid:border-red-600" />
     </div>
     <div class="md:col-span-1">
-      <UiButton size="icon" class="rounded-full h-8 w-8" :disabled="!validNewMonth" @click.prevent="addMonthToCalendar">
+      <UiButton size="icon" class="rounded-full h-8 w-8" :disabled="!validNewMonth" @click.prevent="addMonthToModel">
         <PhPlus size="17"/>
       </UiButton>
     </div>
     <div class="md:col-span-full">
-      <div class="md:grid md:grid-cols-12 md:gap-4 md:items-center">
-        <div class="hidden md:block col-span-1">
-          <ul class="grid gap-y-4 justify-center">
-            <li v-for="(m, i) in model" :key="`num-${m.name}`">
-              <UiButton size="icon" variant="secondary" class="h-8 w-8 rounded-full">
-                <span class="font-bold text-sm">{{ i + 1 }}</span>
-              </UiButton>
-            </li>
-          </ul>
-        </div>
-        <div class="md:col-span-11">
-          <ul ref="monthSortableList" class="grid gap-y-2">
-            <li v-for="(m, i) in model" :key="m.name" class="grid md:grid-cols-12 gap-4 md:items-center text-slate-900 bg-slate-200 rounded-md">
-              <div class="md:col-span-1 text-right duration-200 ease-out transition transform origin-top-right">
-                <UiButton type="button" variant="ghost" size="icon" class="handle rounded-full h-8 w-8">
-                  <PhList size="17" />
+      <div class="border-[1px] dark:border-slate-800 p-4 rounded-sm" :class="model.length ? 'md:grid md:grid-cols-12 md:gap-4 md:items-center' : ''">
+          <div v-if="model.length" class="hidden md:block col-span-1">
+            <ul class="grid gap-y-4 justify-center">
+              <li v-for="(m, i) in model" :key="`num-${m.name}`">
+                <UiButton size="icon" variant="secondary" class="h-8 w-8 rounded-full">
+                  <span class="font-bold text-sm">{{ i + 1 }}</span>
                 </UiButton>
-              </div>
-              <div class="md:col-span-3">
-                <div class="font-bold md:pl-2">
-                  {{ m.name }}
-                </div>
-              </div>
-              <div class="md:col-span-2">
-                <UiInput :id="`month-days-n${i}`" v-model="m.days" class="bg-transparent border-none" type="number" :name="`monthDays-n${i}`" placeholder="Nombre de jours" min="0" />
-              </div>
-              <div class="md:col-span-1">
-                jour(s)
-              </div>
-              <div class="md:col-start-12">
-                <UiTooltipProvider>
-                  <UiTooltip>
-                    <UiTooltipTrigger as-child>
-                      <UiButton type="button" variant="ghost" size="icon" class="rounded-full h-8 w-8" @click="removeMonthFromCalendar(i)">
-                        <PhTrash size="17" />
-                      </UiButton>
-                    </UiTooltipTrigger>
-                    <UiTooltipContent>
-                      <p>Supprimer {{ m.name }} du calendrier</p>
-                    </UiTooltipContent>
-                  </UiTooltip>
-                </UiTooltipProvider>
-              </div>
-            </li>
-          </ul>
-        </div>
+              </li>
+            </ul>
+          </div>
+          <div class="md:col-span-11">
+            <ul ref="monthSortableList" class="grid gap-y-2" :class="model.length ? 'visible' : 'absolute invisible'">
+              <template v-if="model.length">
+                <li v-for="(m, i) in model" :key="m.name" class="grid md:grid-cols-12 gap-4 md:items-center text-slate-900 bg-slate-200 rounded-md">
+                  <div class="md:col-span-1 text-right duration-200 ease-out transition transform origin-top-right">
+                    <UiButton type="button" variant="ghost" size="icon" class="handle rounded-full h-8 w-8">
+                      <PhList size="17" />
+                    </UiButton>
+                  </div>
+                  <div class="md:col-span-3">
+                    <div class="font-bold md:pl-2">
+                      {{ m.name }}
+                    </div>
+                  </div>
+                  <div class="md:col-span-2">
+                    <UiInput :id="`month-days-n${i}`" v-model="m.days" class="bg-transparent border-none" type="number" :name="`monthDays-n${i}`" placeholder="Nombre de jours" min="0" />
+                  </div>
+                  <div class="md:col-span-1">
+                    jour(s)
+                  </div>
+                  <div class="md:col-start-12">
+                    <UiTooltipProvider>
+                      <UiTooltip>
+                        <UiTooltipTrigger as-child>
+                          <UiButton type="button" variant="ghost" size="icon" class="rounded-full h-8 w-8" @click="removeMonthFromModel(i)">
+                            <PhTrash size="17" />
+                          </UiButton>
+                        </UiTooltipTrigger>
+                        <UiTooltipContent>
+                          <p>Supprimer {{ m.name }} du calendrier</p>
+                        </UiTooltipContent>
+                      </UiTooltip>
+                    </UiTooltipProvider>
+                  </div>
+                </li>
+              </template>
+            </ul>
+          </div>
+        <template v-if="!model.length">
+          <p class="col-span-12 text-lg text-center italic opacity-50">Aucun mois pour l'instant</p>
+        </template>
       </div>
     </div>
   </div>
diff --git a/components/calendar/input/TodaySelect.vue b/components/calendar/input/TodaySelect.vue
new file mode 100644
index 0000000..a0b2baa
--- /dev/null
+++ b/components/calendar/input/TodaySelect.vue
@@ -0,0 +1,69 @@
+<script lang="ts" setup>
+import type { CalendarMonth } from '~/models/CalendarMonth';
+import type { RPGDate } from '~/models/Date';
+
+import { PhCalendarBlank } from '@phosphor-icons/vue';
+
+const model = defineModel<RPGDate>({ required: true })
+
+const props = defineProps<{
+  availableMonths: CalendarMonth[]
+}>()
+
+/**
+ *
+ * @param e The name of today's month
+ */
+function setTodayMonth(e: string) {
+  model.value.month = e
+}
+
+// When the model changes, get the month index from the month name
+watch(model.value, (n, _o) => {
+  // If the month value is already an index, return early
+  if (!isNaN(+model.value.month)) return
+
+  const monthId = props.availableMonths.findIndex((m) => m.name === n.month)
+
+  if (monthId !== -1) {
+    model.value.month = monthId + 1
+  }
+})
+</script>
+
+<template>
+  <div class="flex gap-2 items-stretch">
+    <UiInput id="new-month-current-day" v-model="model.day" type="number" name="newMonthCurrentDay" placeholder="Jour" min="1" step="1" class="invalid:border-red-600" />
+
+    <UiDropdownMenu>
+      <UiDropdownMenuTrigger as-child :disabled="props.availableMonths.length < 1">
+        <UiButton size="sm" variant="secondary">
+          <PhCalendarBlank size="18" weight="fill" />
+
+          <template v-if="props.availableMonths.length < 1">
+            Aucun mois disponible
+          </template>
+          <template v-else-if="model.month && typeof model.month === 'number'">
+            {{ props.availableMonths[model.month - 1].name }}
+          </template>
+          <template v-else>
+            Choisir le mois
+          </template>
+        </UiButton>
+      </UiDropdownMenuTrigger>
+      <UiDropdownMenuContent :side="'bottom'" :collision-padding="30">
+        <UiDropdownMenuLabel>Mois disponibles</UiDropdownMenuLabel>
+        <UiDropdownMenuSeparator />
+        <UiDropdownMenuItem
+          v-for="m in props.availableMonths"
+          :key="m.name"
+          @click="setTodayMonth(m.name)"
+        >
+          {{ m.name }}
+        </UiDropdownMenuItem>
+      </UiDropdownMenuContent>
+    </UiDropdownMenu>
+
+    <UiInput id="new-month-current-day" v-model="model.year" type="number" name="newMonthCurrentYear" placeholder="Année" step="1" class="invalid:border-red-600" />
+  </div>
+</template>
diff --git a/models/CalendarConfig.ts b/models/CalendarConfig.ts
index c9c5360..3c3af20 100644
--- a/models/CalendarConfig.ts
+++ b/models/CalendarConfig.ts
@@ -1,6 +1,6 @@
 import { z } from 'zod'
 import type { CalendarEvent } from "./CalendarEvent"
-import { type CalendarMonth } from "./CalendarMonth"
+import { calendarMonthSchema, type CalendarMonth } from "./CalendarMonth"
 import { dateSchema, type RPGDate } from "./Date"
 
 export interface CalendarConfig {
@@ -19,5 +19,6 @@ export const postCalendarSchema = z.object({
   name: z.string(),
   today: dateSchema.optional().nullable(),
   color: z.string().optional().nullable(),
+  months: z.array(calendarMonthSchema).min(1),
   worldId: z.number().int(),
 })
diff --git a/models/CalendarMonth.ts b/models/CalendarMonth.ts
index 7104ce3..4a14df9 100644
--- a/models/CalendarMonth.ts
+++ b/models/CalendarMonth.ts
@@ -10,5 +10,6 @@ export interface CalendarMonth {
 export const calendarMonthSchema = z.object({
   name: z.string().max(64),
   days: z.number().int().min(12),
-  calendarId: z.number().int()
+  position: z.number().int().optional().nullable(),
+  calendar_id: z.number().int().optional().nullable()
 })
diff --git a/pages/i/world/[id]/index.vue b/pages/i/world/[id]/index.vue
index 2505e49..e1df308 100644
--- a/pages/i/world/[id]/index.vue
+++ b/pages/i/world/[id]/index.vue
@@ -90,10 +90,10 @@ const modalOpened = ref<boolean>(false)
       </section>
 
       <UiAlertDialog v-model:open="modalOpened">
-        <UiAlertDialogContent class="grid grid-rows-[auto_1fr_auto] items-start min-h-[66vh] max-w-4xl">
+        <UiAlertDialogContent class="grid grid-rows-[auto_1fr_auto] items-start min-h-[66vh] max-w-4xl gap-6">
           <UiAlertDialogTitle>
             <span class="text-2xl">
-              Créer un calendrier
+              <strong class="font-bold">{{ world.name }}</strong> — Nouveau calendrier
             </span>
           </UiAlertDialogTitle>
 
diff --git a/server/api/calendars/create.post.ts b/server/api/calendars/create.post.ts
index bedafda..b9a3986 100644
--- a/server/api/calendars/create.post.ts
+++ b/server/api/calendars/create.post.ts
@@ -1,5 +1,6 @@
 import { serverSupabaseClient } from "#supabase/server";
 // import type { Calendar} from "~/models/CalendarConfig";
+import type { Calendar} from "~/models/CalendarConfig";
 import { postCalendarSchema } from "~/models/CalendarConfig";
 
 export default defineEventHandler(async (event) => {
@@ -7,7 +8,6 @@ export default defineEventHandler(async (event) => {
   const { data: bodyData, error: schemaError } = await readValidatedBody(event, body => postCalendarSchema.safeParse(body))
 
   if (schemaError) {
-    console.log(bodyData)
     console.log(schemaError)
     throw createError({
       cause: 'Utilisateur',
@@ -17,7 +17,8 @@ export default defineEventHandler(async (event) => {
     })
   }
 
-  let calendarObject: any
+  // Store calendarId for rollback / links
+  let calendarId: number | null = null
 
   // First insert the calendar
   try {
@@ -33,10 +34,68 @@ export default defineEventHandler(async (event) => {
       )
       .select(`id`)
       .single()
-    console.log(data)
+
+    if (data?.id) {
+      calendarId = data.id
+    }
 
     if (error) throw error
   } catch (err) {
     console.log(err)
+    throw createError({
+      cause: 'Serveur',
+      fatal: false,
+      message: "Une erreur inconnue s'est produite pendant la création du calendrier.",
+      status: 500,
+    })
+  }
+
+  // Setup months data
+  for (let i = 0; i < bodyData.months.length; i++) {
+    bodyData.months[i].calendar_id = calendarId
+    bodyData.months[i].position = i
+  }
+
+  // Bulk insert the months
+  try {
+    const { error } = await client
+      .from('calendar_months')
+      .insert(bodyData.months as never)
+
+    if (error) throw error
+  } catch (err) {
+    // If we found an error, rollback the calendar
+    if (calendarId) {
+      await client
+        .from('calendars')
+        .delete()
+        .eq('id', calendarId)
+        .single()
+    }
+
+    throw createError({
+      cause: 'Serveur',
+      fatal: false,
+      message: "Une erreur inconnue s'est produite pendant la création des mois du calendrier.",
+      status: 500,
+    })
+  }
+
+  if (calendarId) {
+    try {
+      return client
+        .from('calendars')
+        .select("*")
+        .eq('id', calendarId)
+        .limit(1)
+        .single<Calendar>()
+    } catch (err) {
+      throw createError({
+        cause: 'Serveur',
+        fatal: false,
+        message: "Impossible de récupérer les données du calendrier créé.",
+        status: 500,
+      })
+    }
   }
 })