要获得两个日期之间的天数，我们可以计算从 0/0/0000 开始到第一个日期和第二个日期的天数并计算它们的差值。
例子：
Input: 2020-04-27 23:35:00, 2018-5-12 12:43:23
Output: 716 days, 10 hours, 51 minutes, 37 seconds
Input: 2014-02-25 05:50:20, 2003-12-13 21:42:12
Output: 3726 days, 8 hours, 8 minutes, 8 seconds
为了计算时差，我们可以计算hours2-hours1、minutes2-minutes1、seconds2-seconds1，并执行一些操作（如第65行到第80行的代码所示）来避免负值。
// Golang program for Calculating the total number
// of Hours, Days, Minutes and Seconds
// between two dates
package main
import (
"fmt"
"time"
)
// This function counts the
// number of leap years
// since the starting of time
// to the current year that
// is passed
func leapYears(date time.Time) (leaps int) {
// returns year, month,
// date of a time object
y, m, _ := date.Date()
if m <= 2 {
y--
}
leaps = y/4 + y/400 - y/100
return leaps
}
// The function calculates the
// difference between two dates and times
// and returns the days, hours, minutes,
// seconds between two dates
func getDifference(a, b time.Time) (days, hours, minutes, seconds int) {
// month-wise days
monthDays := [12]int{31, 28, 31, 30, 31,
30, 31, 31, 30, 31, 30, 31}
// extracting years, months,
// days of two dates
y1, m1, d1 := a.Date()
y2, m2, d2 := b.Date()
// extracting hours, minutes,
// seconds of two times
h1, min1, s1 := a.Clock()
h2, min2, s2 := b.Clock()
// totalDays since the
// beginning = year*365 + number_of_days
totalDays1 := y1*365 + d1
// adding days of the months
// before the current month
for i := 0; i < (int)(m1)-1; i++ {
totalDays1 += monthDays[i]
}
// counting leap years since
// beginning to the year "a"
// and adding that many extra
// days to the totaldays
totalDays1 += leapYears(a)
// Similar procedure for second date
totalDays2 := y2*365 + d2
for i := 0; i < (int)(m2)-1; i++ {
totalDays2 += monthDays[i]
}
totalDays2 += leapYears(b)
// Number of days between two days
days = totalDays2 - totalDays1
// calculating hour, minutes,
// seconds differences
hours = h2 - h1
minutes = min2 - min1
seconds = s2 - s1
// if seconds difference goes below 0,
// add 60 and decrement number of minutes
if seconds < 0 {
seconds += 60
minutes--
}
// performing similar operations
// on minutes and hours
if minutes < 0 {
minutes += 60
hours--
}
// performing similar operations
// on hours and days
if hours < 0 {
hours += 24
days--
}
return days, hours, minutes, seconds
}
// Driver code
func main() {
// Syntax for time date:
// d := time.Date(year, month, days, hours,
// minutes, seconds, nanoseconds, timeZone)
date1 := time.Date(2020, 4, 27, 23, 35, 0, 0, time.UTC)
date2 := time.Date(2018, 5, 12, 12, 43, 23, 0, time.UTC)
// if date1 occurs after date2 then
// swap days since absolute
// difference is being calculated
if date1.After(date2) {
date1, date2 = date2, date1
}
// Calling function and getting
// difference between two dates
days, hours, minutes, seconds := getDifference(date1, date2)
// Printing the difference
fmt.Printf("%v days, %v hours, %v minutes, %v seconds",
days, hours, minutes, seconds)
}
输出：
716 days, 10 hours, 51 minutes, 37 seconds