C# UnixTime convert functions for DateTime

UnixTimeConvert.cs

public static int ToUnixTime(this DateTime dateTime)
{
    return (int)(dateTime - new DateTime(1970, 1, 1, 0, 0, 0)).TotalSeconds;
}

public static DateTime ToDateTime(this Int32 unixTime)
{
    return new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc).AddSeconds(unixTime);
}