Does a flowchart always need to have an end? suppose if its a never ending loop? where even if all conditions and processes have been satisfied, the system will still loop back to the start of the process for lets say the next hour. because the conditions are dependent to the time and date. its a web application BTW...
No, otherwise Apple would not have a street address in Cupertino. Seriously, yes a web app has to stop as soon as possible -have a look at settimeout() and cleartimeout() for time sensitive applications and use events (onclick, etc) to trigger actions.
You might be thinking of cron jobs. You can set one to run every second to achieve solve your problem.