Comment by cgarrigue

Interesting idea but I do not see the point: people are able to compute the same results mentally very easily.

By the way, I would suggest adding an option: how many consecutive days off does the company allow. And which days are absolutely not allowed to be taken.

10 years ago, in my company (based in Japan), taking a day off on the first day of the week (generally Monday unless there's an holiday) was not allowed due to the general meeting kicking off the week. This changed recently in my company but as this meeting is common in many Japanese companies, some companies might still apply this restriction.

Likewise, taking a day off before or after a holiday was not allowed except for some specific days (typically Golden Week end of April/beginning of May, Obon in August, and the end of year/New Year). This changed a few years ago.