When posting datetimes to web services or REST services, you might need to convert the standard .NET DateTime to a UNIX format.
Please note than neither REST, nor JavaScript has its own DateTime format. But some systems based on REST (Java applications for example) have a love affair with the UNIX Epoch datetime format, which is the number of seconds since 1/1/1970.
So in order to convert a standard .NET DateTime to a number of seconds, you need to calculate the TimeSpan between the current DateTime and 1/1/1970:
public string ToUnixEpoch(DateTime dateTime)
{
DateTime d1 = new DateTime(1970, 1, 1);
DateTime d2 = dateTime.ToUniversalTime();
TimeSpan ts = new TimeSpan(d2.Ticks - d1.Ticks);
return ts.TotalMilliseconds.ToString("#");
}
The string returned contains the integer of the timespan.
In some systems you need to add /Date()/ around your timespan, so the resulting UNIX Epoch string looks like this:
/Date(1234567891234)/
To convert the UNIX datetime to a .NET DateTime you reverse the process:
public DateTime FromUnixEpoch(long epochTime)
{
var epoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
return epoch.AddSeconds(epochTime);
}
Some systems will return the UTC time, not the time from the current timezone. To convert from UTC to the current timezone, use the TimeZone class from .NET:
TimeZone.CurrentTimeZone.ToLocalTime(yourutctime)
