Consider the following code
<v-date-picker
v-model="picker"
:first-day-of-week="6"
locale="fa"
></v-date-picker>
<v-date-picker
v-model="picker"
></v-date-picker>
As you can see in the following picture, In Persian calendar month starts by 12th which is the first day of May
I also have this problem, unfortunately it's an open bug in Vuetify:
[Bug Report] Problem with vuetify Persian datepicker year selection #11578 Which is a duplicate of: [Bug] Date picker new month is started at the end of previous month in 'FA-local'.
Personally, I had to user vue-persian-datetime-picker. It's pretty good, a simple api and easily customizable. Still, I hope they fix the problem with v-date-picker
