creating events at arbitrary times

[whatson]

I want to email people on a regular basis, that they choose. e.g. it might be once a week or once a month.
Their frequency will come from a database, and they can adjust it also.

e.g. one row will contain e.g. once a week as the frequency, along with their email address, and they will be emailed once a week, where as another one maybe once a month.

I looked into doing a cron job, but that doesn't seem to be the answer here. Any other ideas?

[swa66]

Easiest is to also store when you last mailed them.
Then iterate through the list on a regular (e.g. daily basis), and send out those that need an update.

If you do it like this, even if it would stop halfway for whatever reason, the next day would pick up the slack, even if it were to start twice for some reason: no doubles would be sent out.

A daily cron entry e.g. would be ideal in my mind.