Any way to get a list of schedule dates?

My google fu fails me. I need scheduling help.

I’m looking for something on the web where I can put in a start date, tell it to repeat every week, 2 weeks, month, etc and it will list in plain text the dates that event falls under in diffent formats. I know I can do this in outlook but thats kind of a pain and messes up my calander. I can just look at a calander and just copy the dates but I’m trying to do it in some automatic and easy way.

Like for example I need to know if at work we have a tool inventory at 5:30pm starting on Feb 13th of this year and every 3 weeks, what date this fall on till Janurary 2016 when these tools at to be turned in.

I have about 70 of this odd schedule events I need to do.