title: Postdating transactions for a bank database
body: <p>I have a financial tracking application where the user can enter transactions for their bank accounts and keep track of spending. I have implemented the triggers I learned from <a href="https://stackoverflow.com/questions/27372310/creating-an-sqlite-trigger-that-updates-bank-account-based-on-transaction-inform">this</a> question to automatically update the account balance whenever a transaction is inserted. I also have triggers for edits, deletions, etc.</p>
  
  <p>The issue that has come up with this is that it does not take the date into consideration. If the user enters a transaction for a month in advance, their account balance is still adjusted. I would like to have a way to make it so the account balance isn't adjusted until that day.</p>
  
  <p>To start, I can write my triggers to only update if the transaction date is today or earlier, but then I need to update the account balance when the time comes. How can I do that?</p>
  
  <p>To answer the "what have you tried" question, I'm not really sure what to try. I have considered setting an alarm to run on a specific date and time, but I'm not sure how to do that properly and make sure that the alarm only runs once. Also, if the user enters multiple transactions that are post-dated, and I create several alarms, I am afraid that will be a battery killer.</p>
  
  <p>How could I implement an alarm to accomplish this in an efficient manner?</p>