Jun 24, 2019 10:09 AM|Yongqing Yu|LINK
According to your code, I am not sure what is the txtPostingDate.Text format?
If you just want to convert the content of txtPostingDate.Text to a date format and save it in session,you could write like this:
Session["PostingDate"] = Convert.ToDateTime(txtPostingDate.SelectedDate.ToString("yyyy-MM-dd")).ToShortDateString();
If not, please tell us what is the txtPostingDate.Text specific value?