1st Year Politics Undergrad here, so I sent in my application last year.
I got my offers in the following dates, having sent off my application on 13th November.
1. York- 16th November- conditional
2. Loughborough- 16th November- conditional
3. Lincoln- 17th November- unconditional if accepted as first choice
4. Essex- 19th November- conditional
5. Lancaster-30th November- conditional. It was annoying that it was the last one to reply as it was the one I was most desperate to hear from as I really wanted to get in. Luckily, this is now my university.
It honestly depends. Three of my friends applied to Durham and didn't hear back until March. One was for medicine, the other two for biology but I understand that it is because it is fairly prestigious.
In terms of Oxford applications, I think it may have been February/March time, as those who got interviews obviously had to wait for those to be assessed before they got an offer.