Which of the following are correctly formed?
Tomorrow I get up at half past six.
Tomorrow I will get up at half past six.
Rules of thumb only, and hardly to be chiseled in stone:
Use "will" when you wish to express a goal or a firm intention.
I've been oversleeping too much. Tomorrow I will get up at 6AM.
Use "get up at six" (that is, without will) when you wish to tell someone about a planned schedule (or something that happens regularly).
Last week I worked the late-night shift, 11PM-7AM, and was sleeping until 3PM. But tomorrow I'm back on the day shift and get up at 6AM.