Hi @Njohneer,
There isn’t a way to get the bi-weekly budgeting option in the Tiller Foundation template. The Foundation template is a monthly/yearly budget template only.
If you prefer to use a bi-weekly budgeting interval the only option is the Tiller Budget (installed via the Tiller add-on). If you’ve spent time customizing the Foundation Template, you can use the Migration Helper in the Tiller Labs add-on to transition your customized transactions/categories/manual balances.
Sorry for any inconvenience.
Heather