In theory, there is no difference between a weekly and an everyday habit. The level of difficulty in developing a new habit involves two things that don't depend much on frequency: the trigger and the size of the discipline.

And, according to the Pareto rule, the trigger does 80% of the job. For example, if you want to gulp a glass of water first thing in the morning, no matter if you do this every day or only on Sundays, the trigger may be the same. In this case, a reminder on your mobile is enough.

"In theory there is no difference between theory and practice. In practice there is." - Yogi Bear

In practice, however, the frequency of your habit significantly affects how quickly you will develop your habit. Again, using the Pareto rule, 80% of habits are MUCH easier to be done every day.

We are creatures of habit. We have daily routines: how we wake up and start our day, how we prepare for work and commute, how we do our work, tackle household chores and winding down at the end of the day.

Adding one new piece to your smoothly-running daily routine is natural. If you want to do something every day, you have multiple opportunities to anchor your new habit to the existing one. You can add a habit to your morning, evening or commuting routines. You can do it while you prepare for work, going back from it or after you pick up kids from the school.

When you do something only once a week, it's much harder to find such a reliable trigger. Out of necessity, you start building your new habit "in the air," without the support of an existing habit.

Once a Week?

For me, Sunday is a special day and my routine is different for that day, so it is the only day when I could've successfully added something new. In any other day, I would have needed a conscious effort to establish a new habit:

"Every day, when I come back from work, I put my backpack in my home office, but on Wednesdays I put it in the corridor and immediately start reading a book."

This is ridiculous!

Frequency may not have much to do with a single successful execution of your new habit, but it has very much to do with how quickly the new habit solidifies.

Repetition, Repetition, Repetition

Creating a habit is actually hammering out a new neural loop in your brain. Repetition is the key to success. And of course, you repeat your new routine 7 times less often if you do it once a week instead of daily.

The loop, however, is not forming only 7 times slower. It's 49 times slower. There is plenty of additional information noise that disrupts the process of teaching your brain what your new habit is.

If at the same time on Monday and Tuesday you do different things, your brain cannot associate time factor with your new discipline.

If you do your new habit in your home office once a week, but you work there 5-6 days a week, the place is another confusing factor.

If you do your new habit on Thursdays after turning off a TV set, you confuse your brain every other day when you turn off the TV set, and so on.

Continuity Works Better

But if you repeat every single day your new routine and each time after the same trigger - in the same place, at the same time or after the same event (OR the same place, time and event) you very clearly communicate to your brain what needs to be done.

In my experience, developing a daily habit is a default option. Every other option is asking for trouble. And if you want to create a new habit that sticks or to develop it very quickly, like in a week, you'd better execute your new habit many times a day.