Anytime Congress authorizes spending or the Executive spends under war power or emergency authorization from Congress. Basically, anytime the federal government spends in the private sector new money is created and becomes someone’s asset.
When taxes are collected the reverse happens as the money enters the government sector and encounters the debt that created it, zeroing both out. Neither taxes nor borrowing can be funding mechanisms for federal spending and only remove currency from the private sector.
There is no real functional reason to even concern ourselves with federal revenue as long as we aren’t at full employment or as long as resources exist to achieve whatever goal money is spent for. Given the fact that we are a net importer and allow extreme wealth accumulation, both causing a currency drain, we should always be spending in deficit. We have no reason to borrow what Congress can create on-demand, so we should end Treasury debt.