DateTime.Now equivalent for TimeOnly and DateOnly?

Question

.NET 6 / C# 10 introduced TimeOnly and DateOnly structs, to represent only a time and only a date respectively.

The good old DateTime struct always had a Now static property which would give you the current date and time.

I was expecting both TimeOnly and DateOnly structs to have similar static properties; like TimeOnly.Now or DateOnly.Today, but they apparently don't.

So, what should I do if I want a DateOnly object representing the current date, or a TimeOnly object representing the current time?

And I would also like to know WHY they decided not to include properties like that on these two new structs?

Answer 1

The solution:

The way to create a TimeOnly or DateOnly object representing the current time or date would be to use the FromDateTime static method along with DateTime.Now. So like:

TimeOnly now = TimeOnly.FromDateTime(DateTime.Now);
DateOnly today = DateOnly.FromDateTime(DateTime.Now);

---

If this is something you repeatedly need in your project, in order to avoid duplication, you could create extension methods on DateTime to convert a DateTime instance into TimeOnly or DateOnly:

public static class DateTimeExtensions
{
    public static TimeOnly ToTimeOnly(this DateTime dateTime)
    {
        return TimeOnly.FromDateTime(dateTime);
    }

    public static DateOnly ToDateOnly(this DateTime dateTime)
    {
        return DateOnly.FromDateTime(dateTime);
    }
}

Usage:

TimeOnly now = DateTime.Now.ToTimeOnly();
DateOnly today = DateTime.Now.ToDateOnly();

Note that this would be not only useful for getting the current date or time as TimeOnly or DateOnly, but for converting any instance of DateTime into TimeOnly or DateOnly.

Another approach would be to have two static classes like the following:

public static class TimeOnlyHelpers
{
    public static TimeOnly Now => TimeOnly.FromDateTime(DateTime.Now);
}
public static class DateOnlyHelpers
{
    public static DateOnly Today => DateOnly.FromDateTime(DateTime.Now);
}

Usage:

TimeOnly now = TimeOnlyHelpers.Now;
DateOnly today = DateOnlyHelpers.Today;

---

Why isn't there a simple property on DateOnly and TimeOnly?

The rationale behind why no Now or Today properties were added to these structs was discussed here in this GitHub issue.

In short, they didn't want to bring in timezones and everything into DateOnly and TimeOnly since that would add extra complexity, so they decided against this, and kept the new structs simple and atomic.

There is some discussion however about whether a property like that could be added to a Clock class (still a proposal, you can follow it here) so that the usage would be along the lines of TimeOnly now = SystemClock.Local.Now, or for DateOnly like DateOnly today = SystemClock.Local.Today or something like that. But that's still undecided.