how to convert tokenModel.ExpiresIn into seconds

Question

I have ExpiresOn for Azure AD token which is a type of DateTimeOffset. My model class is below,

public class AadToken
{
    public string Value { get; set; }
    public DateTimeOffset ExpiresIn { get; set; }
}

and a method returns the above model like below,

return new AadToken { ExpiresIn = accessToken.ExpiresOn, Value = accessToken.Token };

Now I need to convert it into seconds and set like below,

//tokenModel.ExpiresIn needs to convert in sec.

entry.AbsoluteExpirationRelativeToNow = TimeSpan.FromSeconds(tokenModel.ExpiresIn);

How can I do this?

Answer 1

That's like asking how many seconds there are in 2021-08-27 20:10:03. A date is an instant in time, not a duration, so the question has no answer.

You can calculate how many seconds are between two dates, eg now and the target date, eg tokenModel.ExpiresIn - DateTimeOffset.Now. This returns a TimeSpan class with the duration. You can use the TotalSeconds property to get the duration in seconds

var expSpan=(tokenModel.ExpiresIn - DateTimeOffset.Now);
entry.AbsoluteExpirationRelativeToNow = expSpan.TotalSeconds;