I need software that will keep records of time I spend on some computer files I use in my work.?

I work with engineering and land surveying software and find it hard to keep accurate job time since I may work on a number of job names each day, switching back and forth as information requests come in. I use a program called Microsurvey which is almost a clone of AutoCad.

I need software that will keep records of time I spend on some computer files I use in my work.?
ive seen a program called timelogger.Its supposed to record time in each program used. not quite sure how it works though. just an fyi

riding boots