i did poste already the functions for this but here its again
public static class DateTimeExtender
{
#region Functions
/// <summary>
/// Methods to convert DateTime to Unix time stamp
/// </summary>
/// <param name="_UnixTimeStamp">Unix time stamp to convert</param>
/// <returns>Return Unix time stamp as long type</returns>
public static double ToUnixTimestamp(this DateTime thisDateTime)
{
TimeSpan _UnixTimeSpan = (thisDateTime - new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc));
return (double)_UnixTimeSpan.TotalSeconds;
}
#endregion
}
public partial class Form1 : Form
{
public static DateTime UnixTimeStampToDateTime(double unixTimeStamp)
{ // Unix timestamp is seconds past epoch
System.DateTime dtDateTime = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
dtDateTime = dtDateTime.AddSeconds(unixTimeStamp).ToLocalTime();
DateTime localTime = TimeZoneInfo.ConvertTime(dtDateTime, TimeZoneInfo.Utc);
return localTime;
}
private void button_unix_tonormal_Click(object sender, EventArgs e)
{
string format = "dd.MM.yyyy HH:mm

s";
dateTimePicker_date_time.Text = UnixTimeStampToDateTime(double.Parse(textBox_unixtime.Text)).ToString(format);
}
private void button_normal_to_unix_Click(object sender, EventArgs e)
{
// dd.MM.yyyy hh:mm

s
string picker = dateTimePicker_date_time.Text;
string[] split_date_time = picker.Split( );
string[] split_date = split_date_time[0].Split(.);
string[] split_time = split_date_time[1].Split(

;
int year = int.Parse(split_date[2]);
int month = int.Parse(split_date[1]);
int day = int.Parse(split_date[0]);
int hours = int.Parse(split_time[0]);
int minutes = int.Parse(split_time[1]);
int seconds = int.Parse(split_time[2]);
DateTime dt = new DateTime(year, month, day, hours, minutes, seconds, DateTimeKind.Utc);
textBox_unixtime.Text = dt.ToUnixTimestamp().ToString();
// or
// textBox_unixtime.Text = DateTime.UtcNow.ToUnixTimestamp().ToString();
}
}