I am referring specifically to a predictable change and how you calculate the number of days.
In the case of a 4-weekly payment, it is clearly a case of counting up to and including the date on which the last of the old instalments is issued.
However, in the case of the weekly payment, I believe that the number of days should be taken up to the day before the first of the new instalments is issued.
Effectively, 4 weekly payment are all in arrears whereas weekly payments are in advance (liken it to HB payment cycles advance vis-a-vis arrears)
I am basing my whole argument on what is contained in sections 1307 & 1308 of the Tax Credit Guide.
Unfortunately, all the case studies scenarios use 4-weekly payments
