This is a personal project that I've been working on very slowly now on the side for the past 5 years (yes, ridiculously long), using it for myself for a while and now finally have it ready to share to a wider audience. It's a web app for building printed wall calendars that include sun and moon info for each day, specific to the location you choose.
Rather than using accounts, each calendar gets its own unique URL by which it can be accessed. This way there are no accounts, no logging in, no tracking, etc. Everything is deleted 7 days after the last access, or if ordered, 18 months after the last access. There's no email list, no collecting/saving of email, etc. It's for creating and printing calendars; nothing else. This makes it free to try without worrying about getting harassed by remarketing...
I built it with nodejs and pdfkit for creating the calendar PDF that gets sent to the printer (lulu.com). I'm just using file storage of json documents to start with -- I know this is not ideal, but I started simple and lightweight and will fix things if/when needed. In the past I've been overly obsessed with using all the right tools and frameworks, but that can sometimes distract from the simple core goal, so for this I've intentionally taken a different approach (specifically since this is more of a "just for fun" project).
But I don't know -- adoption has been slow so far. Does anyone use printed calendars anymore?
