You track your time religiously, don’t you? Absolutely. Me too. And thanks to our meticulously-completed timesheets, we’re able to bill clients quickly; tell which projects we’ve underestimated on, and which ones aren’t taking us as long as we thought; and improve our estimating accuracy over the long run.

Yep, you and I track our time religiously… except when we don’t. A crisis comes up, you’re working overtime, and you can either fill in your timesheet or squeeze in enough time to ship a quick update to the client and a request for overnight help to a supplier. Not to worry, you tell yourself; you’ll remember how you spent the hours today and enter them later.

Or maybe it isn’t your fault: the spreadsheet you’re using to track your hours got corrupted, one of the kids put a powerful magnet on your backup disk (“But mommy, it makes such a funny noise!”) and the cloud-based backup company you use disappeared overnight, replaced by a salmon cannery whose occupants insist they’ve been there for 20 years. (“What is this ‘KloudStorajPro’ of which you speak? I am a simple salmon canner, and know nothing of peak traffic prediction algorithms, hardware deployment strategies and Series B financing for infrastructure-as-a-service startups.”)

Whatever the scenario, you’re a week behind. Maybe more. And those crystal-clear memories of how you spent your time have melted into a featureless puddle of damned-if-I-know. Now you’re going to have to play detective, and reconstruct the past week or two – kind of the way amnesia victim Leonard had to do in the movie Memento. (Hopefully, the body count in your investigation will be lower.)

The obvious thing to check is your calendar, which can identify appointments, meetings and events, and your task list, especially if it tells you when you ticked items off as complete. But that may still only fill in part of the picture.

If you aren’t sure where to turn next, here are five tools for your temporal detective’s kit that can help you close the case quickly, easily and – most important of all – accurately:

  • Email: Your email outbox may be your single richest source of information on what projects were occupying your attention on a particular day. But it probably won’t capture everything. If your email client supports it, set up a smart mailbox that searches for both incoming and outgoing mail between the dates you’re tracking. Then scroll through and see what jogs your memory.
  • Computer file dates: Your computer logs the dates files were created, last modified and last opened. And not just work documents. Things like chat logs can shine a nice bright light on what you were up to on a given day. Search for files created, last opened or last modified on the dates in question, and see what you – or at least your apps – were up to.
  • Cloud file dates: Don’t just look on your own computer. How about the files and documents you store online? What did you save to Google Docs that day, or upload to Slideshare?
  • Social networks: Did you post anything to Twitter or Facebook that could hint at what you were doing? Ask a LinkedIn question? Check in somewhere on Foursquare or Yelp?
  • Browser history: This is my secret weapon; we do a lot of work through our browsers, from online research to using web apps. If this was an episode of CSI, the browser history would be what I’d be taking into the interrogation room with my chief suspect. (“You’re crazy if you think I can remember what I was up to at three in the afternoon nine days ago!” “Maybe I am crazy. Crazy like a… Firefox.” No, no, wait – “You think my client’s going on a trip down memory lane with you, detective?” “Not a trip… a Safari.”)
Got any timesheet-reconstruction secrets of your own you care to share? Comment away!