clipDate (Month { year = y, month = m }) = Month {
    year  = year . clipDate . Year $ y,
    month = min 12 . max 1 $ m
    }
clipDate (Month { year = y, month = m }) = Month {
    year  = year . clipDate . Year $ y,
    month = min 12 . max 1 $ m
    }
clipDate (Month { year = y, month = m }) = Month {
    year  = year . clipDate . Year $ y,
    month = min 12 . max 1 $ m
    }