28*13=364. Months are different sizes so month*12 would be an over-estimate

Don’t be stupid. They don’t use the same calculation for subscriptions, there they do 12 months. Only for consumption spending they come up with 13 months of 28 days. They could have just done 30 days for 12 months if they were concerned about over estimating. Guarantee 28 x 13 gives better number than 31 x 12.