NikaTime is used to track what you've worked on, so it shouldn't be possible to log time for future dates, right?

Well... Not quite! There are two situations when you can log your time in advance:

You can schedule time off through Slack through the More Actions button, or by typing and sending help in your chat with NikaTime, you can access the Schedule Time Off button and follow the instructions. More about this is in this other article.

You can also do it through the Report Center. You can learn more about it here.

When you usually log the same amount of hours on the same project, after some time NikaTime will start asking you if you wish to log the same hours for the next 3 days or the next week.