func (e *Entry) Weekdays() *Entry {
	return e.Days(Monday, Tuesday, Wednesday, Thursday, Friday)
}
Weekdays runs every MON-FRI at hour 0 and minute 0
package schedule
import (
	"strings"
)
const (
	Sunday = cronDay("0")
	Monday = cronDay("1")
	Tuesday = cronDay("2")
	Wednesday = cronDay("3")
	Thursday = cronDay("4")
	Friday = cronDay("5")
	Saturday = cronDay("6")
)
type cronDay string
type Entry struct {
	expression string
	Command    Runner
}
func (e *Entry) String() string {
	return e.expression
}
func (e *Entry) EveryMinute() *Entry {
	return e.spliceIntoPosition(1, "*")
}
func (e *Entry) EveryFiveMinutes() *Entry {
	return e.spliceIntoPosition(1, "*/5")
}
func (e *Entry) EveryTenMinutes() *Entry {
	return e.spliceIntoPosition(1, "*/10")
}
func (e *Entry) EveryFifteenMinutes() *Entry {
	return e.spliceIntoPosition(1, "*/15")
}
func (e *Entry) EveryThirtyMinutes() *Entry {
	return e.spliceIntoPosition(1, "0,30")
}
func (e *Entry) Hourly() *Entry {
	return e.spliceIntoPosition(1, "0")
}
func (e *Entry) Daily() *Entry {
	return e.spliceIntoPosition(1, "0").spliceIntoPosition(2, "0")
}
func (e *Entry) DailyAt(spec string) *Entry {
	segments := strings.Split(spec, ":")
	if len(segments) != 2 {
		panic("invalid specification of an entry")
	}
	return e.spliceIntoPosition(2, segments[0]).spliceIntoPosition(1, segments[1])
}
func (e *Entry) Weekly() *Entry {
	return e.spliceIntoPosition(1, "0").spliceIntoPosition(2, "0").spliceIntoPosition(5, "0")
}