task vs. thing to do

Hello everyone,

If I’m thinking about what I’m going to do today, can I, for example, say or write something like this:

12,00. Task: call parents
12,00 Thing to do: call parents.

Which one sounds more natural?

Thank you.

To me ‘task’ is out of option here: “something that you have to do, often something that is difficult or unpleasant”. Would sound like a burden, and would be justifiable only if you were not on speaking terms with your parents or found the call difficult to make for whatever reason.
‘Thing to do’ sounds more neutral. Personally, I would script it like: Not to forget.
Others may put it differently, of course.

Thank you, Eugene2114.