When receiving a GMT +0 date string from front-end, how do I make it a GMT +2 Date object in my back-end?

Question

What I receive from the front-end is this:

"date": "2021-06-04T22:00:00.000Z"  

This is the dateTime in GMT+0. How can I now convert it to a Date object in my back-end so that it's 2021/06/05" (5th of June, midnight)?

Here's what I have so far:

CultureInfo culture = new CultureInfo("nl-BE");  
...  
var entity = _mapper.Map<HolidayDate>(h);  
entity.Date = Convert.ToDateTime(entity.Date, culture);  
_holidayDateRepository.Add(entity);  

So I'm setting the culture to my culture (GMT +2). Then I'm mapping my front-end DTO to an entitiy object "HolidayDate" here. Then I want to alter the Date, which right now has the wrong value (GMT +0). How can I make it so that it will get the correct culture/GMT+ +2 date?

Do I do it here in my back-end code, or can I set in in my AutoMapper configurations or another way?

Answer 1

Try this method.

    private static DateTime ToLocalTime(string utcDateTimeString, string timeZoneString)
    {
        var utcDateTime = DateTime.Parse(utcDateTimeString);
        var utcDateKind = DateTime.SpecifyKind(utcDateTime, DateTimeKind.Utc);
        var timeZone = TimeZoneInfo.FindSystemTimeZoneById(timeZoneString);
        var localTime = TimeZoneInfo.ConvertTimeFromUtc(utcDateKind, timeZone);
    
        return localTime;
   }

Usage;

    public static void Main()
    {
       var utcTimeString =  "2021-06-04T22:00:00.000Z";
       var localDateTime = ToLocalTime(utcTimeString, "South Africa Standard Time");
       Console.WriteLine(localDateTime);
    }

List of timezone names. https://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/default-time-zones