Numerous errors at character creation birth date selection, present in every month

[Hasrat]

Because the Eorzean year is longer, some dates on the Eorzean calendar will match with Earth dates twice, so that by the end, December 31 (the end of the Earth year) lines up with the 32nd Sun of the Sixth Umbral Moon (the end of the Eorzean year).

If they were "data entry errors," then most of the month of the Sixth Umbral Moon would effectively be January again, and that would throw off the calendar entirely.

To reiterate, some Earth dates are stretched over multiple Eorzean dates in order to stretch the Earth year into 384 days. There's no error.

Edit, additional: In case maybe there's some confusion here, the dates in parentheses are not the dates selected. The dates in parentheses are the equivalent Earth dates for the selected Eorzean date. Perhaps there is some confusion where you are reading the dates in parentheses as the "translated" Eorzean dates, but Eorzea does not use the (month/day) format.