You have the option to have your function run on a timer to set off at regular intervals. To do this you will need to navigate to the serverless.yml file and add in under the functions > function name:
cron: active: true value: '*/1 * * * *'
The value is the cron function you want it to run on. For help with cron functions check out the Cron Tab Guru. You can also the cron function to be inactive if you want.