What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
You could use the default DateTime field that we have under our "Quick Tools" section to let your users to pick up dates with minutes and hours on them.
1. Click the DateTime field and click the "Time" to enable it.
2. To change the increments on minutes, let's say per 10 minutes, you can change it on the "Properties" of the DateTime field.
You may also want to check a couple of widgets we have related to calendars here: http://widgets.jotform.com/category/pickers.
Do let us know if this helps.