Background: I'm at the company since July 2016, and this is my last month of the timed contract. It's my first job out of college. Once the contract expires (on June 30th) I'm moving out of the city and starting an internship in a different industry.
There are a few things to wrap up while I'm still here. About two weeks ago I was told of two tasks, unrelated to each other, that I'll be expected to complete. It was implied (although not strongly, I might have misread) that I'll be spending this whole month completing the tasks and nothing else will be expected of me (except maybe training my replacement hire if we happen to overlap, but that's unlikely).
There's also an issue of vacation days - I have ten vacation days, which amounts to two free weeks. My boss doesn't want me to use them, he'd rather pay me the equivalent salary for the unused days (it's legal and standard in my country). I thought my boss takes such a stance because he understands the tasks will take up a long time, and I was okay with giving up a few vacation days in return for money.
However, this week the deadlines were significantly pushed forward (again, they weren't explicitely stated, but I expected them to be nearer to the end of June). One of the tasks was pushed on last Monday - when I presented initial results my boss replied that he expects me to wrap it up by next Friday (which was two days ago). Fair enough.
Then, on Wednesday evening the second task was pushed forward to the Friday, too. First he just asked if I'll make it - I replied that probably I won't. He wasn't at the office on Thursday and Friday, but on Thursday morning he sent an email in more direct terms - that I'm supposed either to complete the task on Friday or come to work on weeekend (he didn't mention the first task and I'm not entirely sure if he remembered I'm supposed to do that too). He's also not completely aware of the fact that one of my colleagues is not meeting the deadlines I negotiate with her - and her delays are slowing me down, too. Anyway, I came to work on Saturday and Sunday and completed the tasks, although not nearly as good as I would if I had more time.
I don't think that these tasks are urgent in their nature - they could be completed later. Also, both of them could be delegated to someone else - although I'm probably the most qualified to complete them. However, some additional time to work on them would be very beneficial in my opinion.
Now, my question is - am I in a position to ask my boss for reasons such strict deadlines were imposed? How to phrase such a question? Again - it's possible he never implied that I'll have the whole month to work on the tasks and I just misunderstood.