If you need more time in the day, then you're stuck.
Regardless of dimensions and physics and space-time and all that, as far as we human beings are concerned, we travel through time in pretty much one direction and we don't have many tools available for manipulating that travel.
But if you have too much to do, that's an entirely different problem.
Because, if you've got too much to do, you can cut stuff out.
If you've got too much to do, you can prioritise.
Figure out what's important. Figure out what's unimportant.
Get the important stuff done first, leave the unimportant stuff till later. If you do it at all.
And there's a really, really simple rule of thumb we can use to figure out how important something is ... I'll let you know tomorrow.