what is "error in Date"
can we work past/future date.

Could you be more specific? What exactly where you doing when the error occurred? What was the exact text of the error message? What is your system date set to?

In general, you want your time and date set correctly, if for no other reason than to properly time-stamp your files. However, with regards to COADE software, everytime an analysis is performed, the software writes the time and date back to the ESL. This prevents back-dating the computer. This is another reason you want your time and date set correctly.