package main
import (
"fmt"
"time"
)
func main() {
now := time.Now()
currentYear, currentMonth, _ := now.Date()
firstDayOfMonth := time.Date(currentYear, currentMonth, 1, 0, 0, 0, 0, now.Location())
lastDayOfMonth := firstDayOfMonth.AddDate(0, 1, -1)
fmt.Println(lastDayOfMonth)
fmt.Println(lastDayOfMonth.Day())
}
/*
run:
2020-08-31 00:00:00 +0000 UTC
31
*/