Modify list alerts to send 72 hours prior to date field

Question

I've searched around, and surprisingly I haven't seen anyone with the same specific question.

I have a user that wants to use the Alert functionality on a list, but only send 72 (or 48) hours prior to a date column in the list.

I could use a SPD workflow, but that disallows the possibility of letting users decide what items they want to be alerted on.

Also, a great way to modify the email text for just that list would also be great.

Thank you for your time!

Answer 1

I think the only way to save OOTB subscribing and other features is to stop OOTB mailing job and write new mailing job with same logic of assembling mails except module of deciding the date of sending. In this way you could have some difficulties with updates for SharePoint. You can research the possibility of reuse classes with help of disassembler. May be it'll be easy.