从时间戳获取一年中的第一天和最后一天

Question

Given a time object, t := time.Now(), is there a way I could get a timestamp for the first and last days of that year?

I could do something like d := t.YearDay() to get the number of days through the year, and then t.AddDate(0, 0, -d) to get the start of the year, and t.AddDate(0, 0, 365-d) to get the end of the year, but that seems to brittle as it doesn't deal with leap years etc.

Answer 1

You can use your Time struct object and create new Time struct object using time.Date and time.Time.Year() functions. So, if current time is t := time.Now() then last day in this year in UTC will be lt := time.Date(t.Year(), time.December, 31, 0, 0, 0, 0, time.UTC)

Here's an example:

package main

import "fmt"
import "time"

func main() {
    t := time.Now()
    last := time.Date(t.Year(), time.December,31, 0, 0, 0, 0, time.UTC)
    first := time.Date(t.Year(), time.January,1, 0, 0, 0, 0, time.UTC)

    fmt.Println("Current: ", t)
    fmt.Println("First: ", first)
    fmt.Println("Last: ", last)

}

http://play.golang.org/p/jahjd_mi6K