package main

import (
    "fmt"
    "log"
    "time"
)

const layout = "2006 Jan 02 15:04:05 MST"

func main() {
    dateTime, dateWithTimeTruncated := parseTestDates("2015 Feb 21 11:30:00.0 NZDT", "2015 Feb 21 00:00:00.0 NZDT")
    if !dateOnly(dateTime).Equal(dateWithTimeTruncated) {
        fmt.Printf("dateOnly(%v) was %v, but wanted %v", dateTime, dateOnly(dateTime), dateWithTimeTruncated)
    }
}

// Truncate the time component and leave only the date fields
func dateOnly(t time.Time) time.Time {
    return t.Truncate(time.Hour * 24)
}

func parseTestDates(dateWithTime string, dateWithoutTime string) (dateTime time.Time, dateWithTimeTruncated time.Time) {
    dateTime, err := time.Parse(layout, dateWithTime)
    if err != nil {
        log.Fatal(err)
    }
    dateWithTimeTruncated, err = time.Parse(layout, dateWithoutTime)
    if err != nil {
        log.Fatal(err)
    }
    return dateTime, dateWithTimeTruncated
}