Seconds past midnight

Can anyone tell me an easy way to convert a current time to seconds past
midnight (or the converse, convert seconds past midnight to a current
time)? I have the requisition log with a changetime of seconds past
midnight and I need to compare it to the current time - in order to send
an automatic email out of the status of the requisition. I was sending
the email once a day but, now management wants it sent every 2 hours
without duplicating the email every 2 hours.

Any help would be appreciated.
Kristine Pollard
Director MIS
American Turned Products

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