Comparing two dates without regard to time
I have two dates like this, I would like to compare only dates, ignoring the time. I currently have this:
package main
import (
"time"
//"fmt"
)
func main() {
a, _ := time.Parse(time.RFC3339, "2017-02-01T12:00:00+00:00")
b, _ := time.Parse(time.RFC3339, "2017-02-11T14:30:00+00:00")
x := b.Sub(a)
println(int(x.Hours()))
}
What prints 242
. This is correct, but what I really want to do is compare dates like this:
a, _ := time.Parse(time.RFC3339, "2017-02-01T00:00:00+00:00")
b, _ := time.Parse(time.RFC3339, "2017-02-11T00:00:00+00:00")
Note: minutes / hours / seconds are set to zero - now the difference will be 240 hours.
I couldn't figure out how to do this, is there a function time.SetTime(0, 0, 0)
in Go that I missed, or a canonical way to reset the time for a date?
You can take the Truncate
time to make them round to a multiple of the day.
In your example:
oneDay := 24 * time.Hour a = a.Truncate(oneDay) b = b.Truncate(oneDay)
Find the game board with adapted code here: https://play.golang.org/p/yWIYt3UkiT
If you are using time.Time you have to be careful enough because there may be edge cases at the beginning and end of daylight saving time.
Shameless plugin: I wrote a Date package (in fact, it was sourced from someone even earlier work) to handle dates without causing DST issues.
https://github.com/rickb777/date
You can do for example
a := date.New(2017, 2, 1) b := date.New(2017, 2, 11) daysDifference := b.Sub(a) fmt.Println(daysDifference)
There are other subpackages to handle date ranges, time periods, ISO8601 periods, and time times.