Polish working days, public holidays and deadlines, computed offline with legal citations. Count working days between dates, get the monthly working-time norm (wymiar czasu pracy) per art. 130 Kodeksu pracy, list statutory holidays (including Wigilia 24 December from 2025), check a single day, compute a deadline such as invoice payment terms (date + N days, moved to the next working day under art. 115 KC), and list monthly tax and social-security deadlines (ZUS, PIT, CIT, VAT/JPK_V7M, PPK) moved off weekends and holidays per art. 12 § 5 Ordynacji podatkowej. Use whenever the user asks e.g. "ile dni roboczych w październiku", "wymiar czasu pracy grudzień", "do kiedy zapłac…
