Nodatime create a ZonedDateTime given a time and timezone

Question

Can anyone give me the most straightforward way to create a ZonedDateTime, given "4:30pm" and "America/Chicago".

I want this object to represent that time for the current date in that timezone.

Thanks!

I tried this... but it seems to actually give me an instant in the local timezone which gets offset when creating the zonedDateTime.

        string time = "4:30pm";
        string timezone = "America/Chicago";
        DateTime dateTime;
        if (DateTime.TryParse(time, out dateTime))
        {
            var instant = new Instant(dateTime.Ticks);
            DateTimeZone tz = DateTimeZoneProviders.Tzdb[timezone];
            var zonedDateTime = instant.InZone(tz);

score 11 · Accepted Answer · answered Dec 30 '15 at 00:10

using NodaTime;
using NodaTime.Text;

// your inputs
string time = "4:30pm";
string timezone = "America/Chicago";

// parse the time string using Noda Time's pattern API
LocalTimePattern pattern = LocalTimePattern.CreateWithCurrentCulture("h:mmtt");
ParseResult<LocalTime> parseResult = pattern.Parse(time);
if (!parseResult.Success) {
    // handle parse failure
}
LocalTime localTime = parseResult.Value;

// get the current date in the target time zone
DateTimeZone tz = DateTimeZoneProviders.Tzdb[timezone];
IClock clock = SystemClock.Instance;
Instant now = clock.Now;
LocalDate today = now.InZone(tz).Date;

// combine the date and time
LocalDateTime ldt = today.At(localTime);

// bind it to the time zone
ZonedDateTime result = ldt.InZoneLeniently(tz);

A few notes:

I intentionally separated many items into separate variables so you could see the progression from one type to the next. You may condense them as desired for fewer lines of code. I also used the explicit type names. Feel free to use var.
You may want to put this in a function. When you do, you should pass in the clock variable as a parameter. This will let you replace the system clock for a FakeClock in your unit tests.
Be sure to understand how InZoneLeniently behaves, and note how it's changing in the upcoming 2.0 release. See "Lenient resolver changes" in the 2.x migration guide.

I had to switch to 2.0.0 for the .At function to work... then I had to use: Instant now = clock.GetCurrentInstant(); instead of clock.Now in 2.0.0. — Brian Rice, Dec 30 '15 at 02:47
`At` was added in 1.3.0. You must have been on 1.2.0 before. In 1.2, you'd use the `+` operator to combine `LocalDate` and `LocalTime`. (You can still use that if you like.) But yes, the method for the clock instant has changed in 2.0 also. — Matt Johnson-Pint, Dec 30 '15 at 04:34
In 2.0 you can also use a `ZonedClock` to make things simpler, if you're going to take the current date/time from the same time zone repeatedly. — Jon Skeet, Dec 30 '15 at 11:31
Great instructional code. I would suggest using `DateTimeZoneProviders.Tzdb.GetZoneOrNull(timezone)` instead of `DateTimeZoneProviders.Tzdb[timezone]` to show that this step may not work. — tymtam, Nov 20 '17 at 00:04

Nodatime create a ZonedDateTime given a time and timezone

1 Answers1