This timecard tool seeks to provide a quick way to convert and calculate work hours. I wrote it to keep track of my own work hours and I still use it. Use at your own risk. For example, if it calculates something incorrectly due to a bug, you are ultimately responsible to sanity check the results (but if you find bugs, please let me know--lets squash those!)
Thanks for the feedback and suggestions. Going forward, I'll try to make edits as time permits.