Undated planning: start whenever you like
Almost all my paper planners have no printed dates. It is not an oversight: it is on purpose.
With a dated diary, if you skip a week, those pages stay empty forever. With an undated planner, you simply carry on with the next page. No sheet is wasted.
You can also start at any time of the year: in March, after the holidays, or on the day you decide to get organised. No need to wait for January.
A practical tip: write the date by hand at the start of each page. That small habit helps you pause and think about what matters today.
The Canvartin app works the same way: every planner starts when you add it to your shelf, not on a fixed date.