Overall: Dex isn't open source, but integrates with your Google Calendar, has a Chrome extension that integrates with social media workflows.
We're definitely solving a similar problem, and in the past I was a user of Monica until I found it too much work to keep up with. Monica notably does have more fields and performs functions (like journaling) that Dex does not.
Keep up the good work. Some HN types beg for freeware and yet wonder why they cant escape the rat race. Quality software should be rewarded and should not be free of cost.
Free =/= open source. What these HN types you are so aggravated by are asking for is open source (not free as in beer) software, which some (like me) consider an ethical imperative.
See the entire exhausting body of "Open Source is not Free Software" arguments from fsf apologists. RMS literally stated once he wanted proprietary software to be illegal.
Properly answering the question you asked is a whole can of worms, much like asking "vim or emacs" or "macOS or Windows or Linux" or maybe even "python or ruby or rust / go?".
I agree with open source =/= free but what most comments like “open source alternative to” mean is exactly that. HN is a forum promoting ideas both for the benefit of everyone and / or commercial, yet each time someone showcases their work there is someone posting a “free alternative” post as if it’s meant to mean something. Cargo culting open source is really not doing anyone a favour and instead it is pushing more and more entrepreneurs types away from hackernews. Unless some drug maker made a commercial drug to cure cancer and someone else made a free open alternative to it, i really don't care about free github star whoring on hn.