protected void OnClick(object sender, EventArgs e) { var mark = new Mark() { ValueUuid = (new Guid()).ToString(), MetricsId = cbxMetrics.SelectedItem.Value, TimestampStart = ((long)(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1))).TotalSeconds), TimestampEnd = ((long)(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1))).TotalSeconds), Value = tbxMark.Text }; _db.AddMark(mark); }