private static Reader <Enviroment, string> FormatDay(DateTime day)
 => from colorized in day
 .Day
 .ToString()
 .PadLeft(WidthOfWeekDay(day.DayOfWeek))
 .Colorize(ColorService.WeekDayColor(day.DayOfWeek))
 from background in colorized
 .ColorizeBg(ColorService.DayColor(day))
 select background;
 private static Reader <Enviroment, string> FormattedWeekDay(DayOfWeek day)
 => ToShortestDayName(day)
 .PadLeft(WidthOfWeekDay(day))
 .Colorize(ColorService.WeekDayColor(day));