I did something, much simpler, some time back in Google Sheets. Around year-end, I go and edit the location of the starting dates each month (drag around, some formatting). I also like the weekdays lined up instead. Use it more as a bigger-picture timeline/schedule for the year, for the family, and me.

Here is the template from last year that I shared with friends. If you are looking at it, take this as a base or an idea and build on it — finances, big life events, travel, etc.

The “Year” tab is kinda like a big-picture plan of where family members are in their years, education, and, hence, significant life events. As the months go by in the year, just fold/hide that portion.

https://docs.google.com/spreadsheets/d/1YwAf8vgVR0FbTU6n1dVO...

PS. I’m tinkering with moving to a plainer text format this year, in MarkDown planning for a 10-year, 20-year, 30-years, and then kinda brain-simulation of what might be in 50 or even 100 years after I’m gone. I plan for the family/generation as an entity and I just insert myself as one of the role in it. ;-)