Ideas for how to create a reminder notification

hi. looking for ideas on how to go about setting up a reminder for my system.

we register patients who then get a SMS message the next day with a link to a gravity form. the link contains entry ID and i use the REST API and a webhook to display the GF entry for that ID, if it exists already. The patient fills in the empty fields and submits, which updates the entry of the same entry ID.

we need to send a reminder text out at 24 hours later IF they havent filled in the form. we only want to send one reminder.

i need ideas on how to go about this. i had an idea to maybe write a php script that uses the API to go over every entry created on that day, and if a specific field is empty (one of the fields the patients must complete), then generate the SMS notification. I could have a cron job to run the script every day.

are there any easier / better solutions?