Proposal Details

While attempting to port over from Ruby code to Go, I ran into an issue where I needed to set a variable of type time.Time to the maximum of three different times. The maximum here would apply to the farthest in the future time. In Ruby this involves putting the three times in an array and calling the max method on the array.

my_time = [someTime, someTime2, DateTime.now].max

This doesn't work in Go currently because the slices.Max method only works on slices where of type cmp.Ordered which time.Time is not.
All time.Time's can be converted to an int64 Unix representation which would satisfy the cmp.Ordered requirement for using slices.Max and slices.Min. However, this wouldn't work for times before 0 Unix time.

I'd instead purpose adding Min and Max functions for the time package. They'd work by just using the Before and After methods that already exist in the package

func Max(x Time, y ...Time) Time {
	maxTime := x
	for _, val := range y {
		if val.After(maxTime) {
			maxTime = val
		}
	}
	return maxTime
}

func Min(x Time, y ...Time) Time {
	minTime := x
	for _, val := range y {
		if val.Before(minTime) {
			minTime = val
		}
	}
	return minTime
}

// Usage
thatTime := time.Max(someTime, someTime2, time.Now())

The function signature is just like the min and max built-in functions where at least one parameter is required, that way we can just return that value if no others are passed in. The first parameter would also just get used as our base for finding the min or max of the times. This also prevents us from unintentionally returning the time.Time zero value in the Min function