Calculates a date and types it into any program.

Call this tool from a script using [Rofi](https://github.com/davatorium/rofi), [Dmenu](https://tools.suckless.org/dmenu/) or similar.

Supported commands:
  today
  tomorrow
  yesterday
  daybeforeyesterday
  dayaftertomorrow
  next<weekday> (e.g. nextmonday)
  last<weekday> (e.g. lastsaturday)