2021 What I sowed today

You mean like this Eyren

Sort of - I write out the planting date, quantity, etc in my gardening notebook, since once they're done I can't change them. My planned layout, on the other hand, is very much subject to change, which is why I keep it in electronic format:

   

I do a month-by-month plan, as recommended by Huw Richards, as it allows me to see more easily where gaps are going to open up, and thus keep the beds full all year round as much as possible.

(This is in Mac Numbers - we use Macs for work because we're an academic institute, so I switched a long time ago!)