When Do I Have To Do The Long Drive?

So my boss yesterday/Thursday asked if I could come in to work tomorrow/Saturday and, after trying to think if there was anything I absolutely had to do and coming up empty, I said yes.

But there is something I kinda could have done tomorrow/Saturday.  Last week Mother asked me to drive all the way down to my brother's place and give my niece presents she asked my folks to get for her.  I don't enjoy a 45-minute drive, but I was prepared to do it.  Last week my sister-in-law told me they were out of town, so this weekend would've been the "perfect" time to do it ... until I volunteered to come in and work.  I guess I could still do it tomorrow/Saturday; it would just have to be after work and probably after dinner.  Or, I could do it Sunday before the Gold Cup Matches.  But if I had to drive all the way down to my niece's, I prefer it to be the only thing I do that day.  And that plan is ruined unless either 1) I get to do this drive possibly next weekend (I might be busy then, too) or 2) they come up here and get the gifts from us.  The latter would be a huge burden off my chest, but it probably won't happen.