Best way to prompt user for time entry??

[roscoe]

I've built a crazy spreadsheet that uses VBA to extract data from our server to create a graph with time as the X axis. I need to provide a way for users to manually add data points to the graph. These points will be a time (X-value) and a constant (determined by the code based on a user-selected category) as the y value. The code will drop these onto a sheet in the right place. Problem is, I'd rather not just let them type one in (Excel is not robust to typos in date fields).

To create the initial graph, I currently use spin buttons coded to cells with dates. Spinners for month, week, day, and hour prevent the user from fat-fingering in an entry. They seem to like that, so I'd like to do something similar when I then ask them for the data points described above.

Some manual categories will require two times (start/stop), others just one. I'm envisioning a user form with two serial dates/times preloaded with spinners to adjust each (ignoring the second one if nor required). Also I'm thinking radio buttons to allow the user to select what series category the time should be placed in. As a final thought, I'd like to use the user form to edit values already entered, not just add new ones.

I've never done user forms, let alone spinners inside of one. Can somebody link me to an example somewhere to get me pointed in the right direction?

Thanks!