Polish Underground State's Day
September 27, Friday
September 27 – Polish Underground State's Day, Dzień Podziemnego Państwa Polskiego, set on the anniversary of the formation of Service for Poland's Victory, established in 2013.
Polish Underground State's Day in other years
- 2021 September 27, Monday
- 2022 September 27, Tuesday
- 2023 September 27, Wednesday
- 2025 September 27, Saturday