Например,
package main
import (
"fmt"
"time"
)
func monthInterval(y int, m time.Month) (firstDay, lastDay time.Time) {
firstDay = time.Date(y, m, 1, 0, 0, 0, 0, time.UTC)
lastDay = time.Date(y, m+1, 1, 0, 0, 0, -1, time.UTC)
return firstDay, lastDay
}
func main() {
var (
y int
m time.Month
)
y, m, _ = time.Now().Date()
first, last := monthInterval(y, m)
fmt.Println(first.Format("2006-01-02"))
fmt.Println(last.Format("2006-01-02"))
y, m = 2018, time.Month(2)
first, last = monthInterval(y, m)
fmt.Println(first.Format("2006-01-02"))
fmt.Println(last.Format("2006-01-02"))
}
Выход:
2018-10-01
2018-10-31
2018-02-01
2018-02-28
Детская площадка: https://play.golang.org/p/TkzCo9jLpZR