The agent reads the Amazon calendar
Every conversation now knows today's date, your marketplace's clock and the Amazon events ahead. Ask it to hold spend back until a date and it sets a ceiling on each target with an exact end, then hands back.
Prime Big Deal Days, Black Friday and Cyber Monday are in the agent's calendar for the marketplaces that run them, with the run-up before each. When you ask for a dated hold, it caps each target rather than touching your goal, and every cap carries the day it ends, so nothing has to be remembered.