Ask HN: Free service for scheduling SMS alerts?

Is there a service out there that will send you texts with custom content and designated times? I know strictly speaking this isn't "free" on the backend, but it's low cost enough I thought there might be a free service that covers the cost in another way. My quick Google search turned up only paid options, surprisingly.

For example, send a text every Wednesday at 7pm to remind me to take the trash out.