03-02-2017 07:07 AM
I'm not 100% sure what you are trying to do here, but here are couple things that might be what you're looking for:
It's possible to change the type of an existing history record, just click the dropdown highlighted in the screenshot below to change the history to a To-do for example.
If you are trying to create a new To-do that should be completed at a later date, then a Follow-up activity can be created by clicking the button highlighted below.
You'll then be able to set the follow-up activity to be a To-do, and set a new date for it.