I use the excellent TimeTracker by ABS to track my client work on my Android phone. I recently managed to trash the app and data with a misguided attempt at an upgrade, but fortunately I had taken a backup with Rerware's MyBackup.
I copied the data from the SD card under /rerware/MyBackup/AllAppsBackups/AppsMedia_2011_06_04/Apps/de.abs_net.TimeTracker_79.zip to my desktop, unzipped, and dig into it with sqlite3. It was fairly straight forward to find what I needed, but the 'start' and 'stop' times in the 'period' table were in a format that looked like UNIX seconds since the epoch, but the numbers were too long.
ABS's Volker Lehnen answered my request for pointers promptly, with exactly what I needed:
the value in start, stop represent the number of miliseconds since Jan. 1. 1970, midnight GMT (Date.getTime() in Java)
I tweaked my SQL query to generate a report with the Client, Project, Task, Start, Stopped, fractional hours, and comments on each work item. Here it is in case it helps anyone else:
SELECT datetime(start/1000,'unixepoch','localtime'), datetime(stop/1000,'unixepoch','localtime'), round((stop - start) / 1000.0 / 60.0 / 60.0, 1), client.name, project.name, task.name, period.comment FROM period, task, project, client WHERE period.task_id = task.task_id AND task.project_id = project.project_id AND project.client_id = client.client_id ORDER BY client.name;
Which resulted in something like this:
2011-04-25 22:13:16|2011-04-25 22:57:14|0.7|FooClient|HITSS2|proposal|review appdev doc. 2010-09-14 08:09:53|2010-09-14 19:35:03|11.4|BarClient|SID|work|dig into schema, map fields, find missing 2010-09-15 19:31:00|2010-09-15 20:01:54|0.5|BarClient|SID|work|start parsing changes ...
Easy enough.