Hi @David, thanks for your support and for the feedback. I feel privileged that both you and @johndavies24 think highly of my intelligence, but I would urge you both to consider Hanlon’s razor when dealing with me: Never attribute to malice that which is adequately explained by stupidity. 
The 12 weeks switch happened as part of the intro to my weekly progress report for the last period, and I made the naive 3 months * 4 weeks calculation without realising that by doing so I was shaving off 4 weeks of the year (!).
I’ll just go with months instead, and is what’s being done everywhere else. Thanks for pointing this out! 