Rules
Federal Holiday Business Day Counting: Project Dates
Federal holiday business day counting with a real 2025 Memorial Day example, the one-day date shift, and a formula for rebuilding the schedule.
Topic
federal holidays
Rules
IRS response deadlines: calendar days, not business days, and when dates move
Most IRS response deadlines count calendar days, not business days. This explains start dates, weekend and holiday moves, postmark proof, and missed dates.