If you want to edit your Automation you have to inactivate it first. If you inactivate an Automation, the contacts will stay in that step they are staying right now and they will move forward if you republish your Automation again. 


Let’s see an example:

You have a contact in “wait for 24 hours” section for 16 hours. You inactivate the Automation for 4 hours. When will your contact get the next email?

The answer is: in 4 hours. 


We save the date and time when a contact enter a wait section and we save it. If you are inactivate the campaign during this time it doesn’t matter, because after republishing the automation we will check the saved time stamp. 

But new contact won’t enter the Automation while it is inactive.