Is it possible to allow users to change the information they have entered in a form?

Is it possible to make a form that I can later go back and update the information if it does change? (ie building request for a room at 12pm and then they would like to change the time to 6pm)

Yes, you may use the save and continue later method in order to allow the users to change the information they have previously entered on the form, but note that their submission will not be recorded until they click on the submit button, more details can be found here: https://www.jotform.com/help/97-How-to-Save-Forms-and-Continue-Later 

You may also allow your users to submit the form with the initial information and change it if needed on a later date, this guide will help you with that: https://www.jotform.com/help/40-How-to-Let-Users-Update-Their-Form-Submissions-at-a-Later-Date 

I hope this helps.