Convert to Unix Epoch Time

private string ConvertUnixEpochTime(long epoch)
{
    try
{
long baseTicks =  621355968000000000;
long tickResolution = 10000000;
long epochNegative =  1000000000;
long epochTicks = (epoch - epochNegative * tickResolution) +  baseTicks; string date = new DateTime(epochTicks,  DateTimeKind.Utc).ToString();
return date;
}
catch (Exception exp)
{
}
return string.Empty;
}

Kullanımı :

private void button1_Click(object sender, EventArgs e)
{
txtMesaj.Text = ConvertUnixEpochTime(epoch format);
}