now.go
func (now *Now) BeginningOfMonth() time.Time {
	y, m, _ := now.Date()
	return time.Date(y, m, 1, 0, 0, 0, 0, now.Location())
}
func (now *Now) BeginningOfMonth() time.Time {
	y, m, _ := now.Date()
	return time.Date(y, m, 1, 0, 0, 0, 0, now.Location())
}
// BeginningOfMonth beginning of month