// NB: this struct should always be kept normalized (i.e. mon should
// be < 12, 1 <= day <= 31 &c), so use AddMonths(), AddDays()
// instead of modifying the member fields directly!
// NB: this struct should always be kept normalized (i.e. mon should
// be < 12, 1 <= day <= 31 &c), so use AddMonths(), AddDays()
// instead of modifying the member fields directly!