Ceil func Ceil(t time.Time) time.Time Ceil - takes a datetime and return a datetime from the same day at 23:59:59. package main import ( "fmt" "github.com/Goldziher/go-utils/dateutils" "time" ) func main() { d, _ := time.Parse("2006-01-02", "2009-10-13") fmt.Println(dateutils.Ceil(d)) // 2009-10-13 23:59:59 +0000 UTC }