Replying to UCAS choices

I have gotten all five of my offers , and have been given a date in which i have to reply , but the problem is i have a visit day booked for city university, one of the two unis Im considering for a firm choice , which is after my reply date so is it possible to extent the duration of my replies to my offers to at least the end of the march, where my deadline to reply to my unis is 3rd of march?

Generally you can't get more time, when did you get your last offer?

30th of January

The earliest ucas deadline is march 31st so you should have more time.

just realized its may not march