We have been tracking allowance in a wiki for several years. As busy parents we usually forget to update the kids ledgers until weeks after their birthdays. The last time this happened we took notes about the steps to correct their allowance retroactively to correctly reflect their annual raise.
The follow three steps position the ledger for the specific kid and the calculator open to the left of this page.
First, open Ledger for Oldest Child.
Second, shift-click Allowance Calculator.
Third, drag this page to the right of the calculator.
We edit this calendar item to the child's most recent birthday. This represents the end date of their previous rate of allowance.
10 JUN 2019 End
We calculate the new opening balance by importing values from the allowance calculator but overriding the period for this computation.
Rate (dollars / week) Balance (dollars) End Start Allowance (dollars / week) CALC End - Start SUM Period (week) CALC (Period * Allowance) + Balance SUM NewOpeningBalance
Our final steps are to edit the kid's ledger to reflect their raise. We change the OpeningBalance to match NewOpeningBalance. We change their Start date to their most recent birthday (matching the End date on this page). Finally, we correct Age to match their current age. Now the Allowance Calculator will correctly reflect the increase in their allowance.