Dear Stata folks,

I have a dataset with patient_ids, days and a measurement(outcome). Patients may have more than one measurements per day. The number is unequal between patients and days. Let's say that it is the BP measurements.
The days are in %td format but not consecutive, since some patients may non have measured their BP a day and then measure it the next days. Patients are advised to do these measurements for 28 days but some did it for less and few others did so for more.
I want to create a consecutive day variable so as to have 0 measurements when they have not measured their BP, instead of having only the measurements for the days that they did measure.
Any help please? Whatever I saw in different posts doesn't work for my case.
Thank you in advance.