I've researched on some ways to be productive(i.e. wasting my damn time). And I completely overlooked the calendar.
Now you should manage your time in blocks. That means for every task you block a time in calendar. One that works for me is Google Calendar, yes I know Google! But I can't found reliable alternative if you've some alternative mail me.
With this method I know at what time I supposed to do something. It's that easy, don't ever listen to some productivity guru, who tells you he manages his whole life in Notion or some fancy apps like that. Being productive is easy, you just need to have a strong will to do things that you actually don't want to do.
So, just use calendar it made me very productive.