Arbor Day Holiday 2024. Arbor day is observed in spring for the united states but globally dates vary depending on the region's climate and planting season. National arbor day is always celebrated on the last friday in april, but many states observe arbor day on different dates based on the best tree planting times for their area.
See arbor day 2024 details. Arbor day is an annual celebration of tree growing and a national holiday in the us.