One of the major differences between scheduling stuff and putting stuff on your To-Do Lists is that when you plan something in your to-do list, it does not necessarily mean you should finish them today. There is no urgency.

You have no reason to rush them all today. They are just sitting there ready to be addressed whenever you feel like addressing them. This could be today or any other day. The result of this would be a delay in when you started doing those things, and not in a delay in whether or not you have taken care of these things. You did not forget those tasks or leave them behind. You handled those tasks completely. It doesn’t matter when you handled them. They are just gone, and that is what matters. It doesn’t make a difference whether or not you handled them today. The presence of items on your to-do list means you should do them, regardless of the time you pick to accomplish that. You only put something on your to-do list if you are supposed to get it over with, regardless of when you decide to do so. It will always be up to you when to attempt getting those items over with if these items are not at all urgent (That is, Important but not urgent tasks). Also, your to-do list contains all that you are supposed to take care of currently. If something doesn’t make it to your to do list, you shouldn’t try to deal with it at the moment or for the time being, at least until you finish all the items that are already existing on your current to-do list.

This is not the case with calendars. If you schedule something for a particular day, there is an indication that this is the day that you are supposed to address this item in it. If you delay handling this task, you will then be not adhering to your schedule or your calendar. Things gets a sense of urgency even if they are not urgent themselves, just because they are scheduled to be done on a certain day or date in your calendar. If a target is important but not urgent, there would be no obligation to pick or choose doing it now over just having fun and not giving a damn about it for the time being, until maybe the only motivation to get it over with is to wipe it out or cross it out from your to-do list, and free the mental space that is occupied because of it. If a task is important but not urgent, the only way to make you want to get it done despite that would be to make it urgent by specifying a time interval during which you should attempt to finish it, and that happens by scheduling it in a calendar. There is a case to be made for attempting to arbitrarily schedule tasks that there is no absolute indication for specifying a particular date for handling them in your calendar just for the purpose of being productive. Even if these tasks could really be pursued at any time in a certain week, making it an obligation to aim at finishing it in a certain day or on a certain date is okay, for several reasons, one of which is that this makes you understand on an unconscious level that this task should be finished at that time without you deciding whether or not it would be a good idea to do it at that time. It means that you want to deal with this thing or to-do list item today, instead of just address this task or item whenever you feel like it this week, because there is no obligation to exert effort in doing something that you are not sure whether or not it is a good idea to attempt to handle this task today as opposed to any other day this week or those couple of weeks or this month.

Maybe trying to explain this rationally might not be convincing enough, or might not even be the reason why this is helpful, but the finding here cannot be denied. Calendars should contain what you want to do everyday, and Calendars should contain what you want to do today or on any particular day whatsoever. And this should take place without cancelling your dependence on to-do lists as a source of, as a source that gathers, or as a source that contains all the tasks that are required to be done by you these days, currently, for the time being, this week, the only tasks that are ahead of you at the moment, or the only items you should pick any of them randomly and attempt accomplishing it but not try to pursue something outside of them until further notice. The to-do list is a place that contains the things that you should not attempt to address anything else that is not one of them, that is outside of them, or that is not mentioned among them in the to-do list until you finish all the tasks that are currently found on your to-do list first. Of course there could be future plans for stuff that you should take care of after the current steps mentioned in your current to-do list, but that should be found in some kind of place specified for such future, total, or holistic plans, or plans of the bigger picture, or monthly or yearly plans, and not a current stuff to be dealt with to-do list. Regardless of how perfectly your to-do list contains everything that is required to be done by you at the moment, currently, these days, or for the time being, or how perfectly your to-do list contains all that is ahead of you at the moment or all that you should not attempt to address something that is not among them until you finish them all first, your calendar systems should contain all that you want to do on any particular day whatsoever or on any particular date whatsoever. What you want to do today should be fully scheduled in your calendar systems, and also what you want to do on any particular day whatsoever should be fully scheduled in your calendar systems, not necessarily before this day comes or arrives by a very long time, but at least that should be the case when this day arrives or before this day by a reasonable duration of time when you are able to realize exactly what should take place on such a day.  Do not put stuff on your to-do list only and believe that this is enough to make you productive. Also, as has been stated before elsewhere, do not substitute calendar based productivity systems for to-do lists entirely, but make them complement each other. There is a benefit that you can only get from calendars that to-do lists alone will not let you reach. Put what is ahead of you on a to-do list that is for whatever executive tasks that lies ahead of you. Aside from this, always indicate in a calendar based system what you should be doing today. Any entry you make for a day in the future is something that you figured out would be a good idea to be scheduled this day. But for the current day (today), you should ask yourself before you begin this day, what do I really want to get done today that I do not want to postpone or defer to any other day in the future, and then add it to this day’s scheduled tasks in your calendar. The to-do list contains all that you should randomly finish during this phase or these current days, but your calendar will be the only location that specifies exactly what you are supposed to take care of at any particular day or date.