You mighty be interested in the alarmmanager extension
Taifun
thanks for your help. i still got a problem here
the code is running like this
when i switch this button
but i need the reminder that not directly pop up like this. i need the notification based on the date like "event reminder"
what i need to change by this code?
Simple notification extensions are not able to send a notification at a defined time in the future... you need another extension... read my previous answer
Taifun
what is your recommendation?
Use the alarmmanager extension
Taifun
I have this problem (vaccination schedule)
Continuing the discussion from When the user enters the child's birth date, a list of all his vaccinations appears:
i still cannot do this
You want to enter a child's birth date, and return their vaccination history ?
or is your "problem" related to this:
i have 2 problems. the notifications and the upcoming vaccination schedule
Please elaborate
Taifun
Have you seen
and
Parts of them may help you solve your problem.
yes i applied your blocks and combine with other blocks but i got this warning
the blocks are like this
by the way for the quantity, is it okay if i put the vaccine type as a quantity? i mean the vaccine type have a different time like for HepB is 1 month after DoB, Polio is 2 months after DoB
your Blocks on the left; the Blocks I used on the right. 
When you modified the Blocks to add to your existing blocks, you seemed to have introduced errors.
No, the quantity must be the number of months as coded . You have to adapt this code to work with multiple vaccines in your app.
Yes, I understand. You can reproduce some of these Blocks for each vaccine or write the critical code as a Procedure. The value in TextBox6 must change for each individual vaccine. Currently the example is hard coded to 6 months, you need 1 month for HepB, 2 months for Polio.
Perhaps this example will help:
timeBetweenDates.aia (3.5 KB)
what should i use for this? check list, list view or what
You can use any of those methods Jinsol or a ListPicker. Use what you are most comfortable coding. 
Here is an example using a ListView. This code works on my Android 13 and the old emulator. It uses the basic Notifier, not a push notification.
I adapted the timeBetweenDates posted above to use a ListOfPairs for the vaccinations and used a ListView to select the vaccine to check.
thank you very much. could i see the aia file so i can reproduce some blocks? i think i am starting to understand how this app works
i reproduce your blocks like this but i got some problem
as you can see, the DoB is in dec 2022, vaccination date in feb 2023, and vaccination due is in nov, 2023... thats mean the vaccination is on time but it got red
That AddMonths should appear on only one side of the >= (<=?) comparison.
You put it on both sides, cancelling it out.
Here is a version of that code that runs on an Android 13
But i need the vaccination date and DoB, not the block “clock1.Now” what should i do?
Adapt the responses as appropriate. To keep this simple the app does not keep track of whether the vaccine was given on not. If the proposed date passes, the app displays this in red. You can make this behave any way you like. 
However as coded dates in the past always will show in read. If you want a different behavior you will have to provide the date the vaccine is actually administered. 