Honoring your time decisions versus adjusting due to other circumstances

I like to weekly plan, so last Sunday I sat down and “thought downloaded” all my tasks for the week, and then assigned them to days of the week. I did very well M-F, when I’m at my office job, but ran into problems on Sat. I had planned a few hours of indoor work on my side business back on Sunday, but when Saturday arrived it was the best weather day we have had in Michigan since October. Sunny, 65 degrees. So I decided to not honor my decisions from earlier in the week and spend the day outside cleaning up the yard after winter and getting my pots set up, as well as my deck and patio.
It was a great day, a ton of work got done but none of the side gig work I had planned.
Am I making a mistake in weekly planning because circumstances do come up during the week that make the plans overcome by events? Or am I letting my primitive brain win by saying I’d much rather be outside and do this other work instead of indoors?
Or is it OK to let go of the planning decisions I’ve made, knowing I will have to move those tasks since everything needs to be done eventually.
Or, of course, I could be overthinking this and I should just move on with my life :o)
But I am diligently doing the SCS work every month.