sundayStartWeek

sundayStartWeek :: Day -> (Int, Int)
time Data.Time.Calendar.OrdinalDate
Get the number of the Sunday-starting week in the year and the day of the week. The first Sunday is the first day of week 1, any earlier days in the year are week 0 (as "%U" in formatTime). Sunday is 0, Saturday is 6 (as "%w" in formatTime).
fromSundayStartWeek :: Integer -> Int -> Int -> Day
time Data.Time.Calendar.OrdinalDate
The inverse of sundayStartWeek. Get a Day given the year and the number of the day of a Sunday-starting week. The first Sunday is the first day of week 1, any earlier days in the year are week 0 (as "%U" in formatTime).
fromSundayStartWeekValid :: Integer -> Int -> Int -> Maybe Day
time Data.Time.Calendar.OrdinalDate