Compute 3 New Date Fields What is the best way to output 3 new dates relative to the first date? For instance, I have a date field called "medication_start" = 1/1/2010. I would like three new dates generated in 3 new fields in 6, 12, and 18 months from the start date.

Period 1 (6 months): 6/1/2010
Period 2 (12 months): 12/1/2010
Period 3 (18 months): 6/1/2011
You could use something like Computed Field for this or you can write your own custom module. You could hook into node save using hook_node_presave (since it acts on save and presave) and calculate the other 3 fields that you need to save. Either way should work pretty well. You would just use php date functions to calculate the new dates either way. There are a bunch of examples for computed field online and in their documentation you could use to draw inspiration from.