If you want to reopen the dates that you closed before, you may reopen it through iPad by following steps:
Settings > Business Settings
find the specific module that you have set before, for example Closed
scroll down to the calendar, and press on the orange dates that you choose before, while you press it again it will become grey
After release the dates, press the orange < Business Settings to save it
After remove the date from closed module, you may check by your inline booking page to see if it set up successfully.
If you also enable Google map booking button, the new opening time will update after 24 hours.
