now.go
func (now *Now) BeginningOfQuarter() time.Time {
	month := now.BeginningOfMonth()
	offset := (int(month.Month()) - 1) % 3
	return month.AddDate(0, -offset, 0)
}
func (now *Now) BeginningOfQuarter() time.Time {
	month := now.BeginningOfMonth()
	offset := (int(month.Month()) - 1) % 3
	return month.AddDate(0, -offset, 0)
}
// BeginningOfQuarter beginning of quarter