测试基于时间的字段是否有意义？ （golang）

I have several structs with fields of type time.Time. I'm wondering what's the best practice to test them? Should I simply set the time.Time fields to nil and test the rest of the struct (i.e. reflect.DeepEqual)? Otherwise is there a way make the time deterministic? Given the function below how would you test it?

type mystruct struct {
    s string
    time time.Time
}

// myfunc receives a string and returns a struct of type mystruct
// with the same string and the current time.
func myfunc(s string) mystruct {
   return mystruct{s: s, time: time.Now()}
}

In case you need create a fake for time.Now() you can create TimeProvider and use it for getting real time.Now() or fake it.

This is very simple example

package main

import (
    "fmt"
    "time"
)

type TimeProvider interface {
    Now() time.Time
}

type MyTimeProvider struct{}

func (m *MyTimeProvider) Now() time.Time {
    return time.Now()
}

type FakeTimeProvider struct {
    internalTime time.Time
}

func (f *FakeTimeProvider) Now() time.Time {
    return f.internalTime
}
func (f *FakeTimeProvider) SetTime(t time.Time) {
    f.internalTime = t
}

func main() {
    var t MyTimeProvider
    f := FakeTimeProvider{t.Now()}
    fmt.Println(t.Now())
    fmt.Println(f.Now())
}