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International Dark Sky Week

Also known as

National Dark-Sky Week (until 2008)
National Dark Sky Week (until 2008)
IDSW (since 2009)

Observed

for 8 days starting on April 1st (2003)
for 8 days starting on April 19th (2004)
for 8 days on an unknown date (2005)
for 8 days starting on April 23rd (2006)
for 8 days starting on April 17th (2007)
for 7 days starting on March 29th (2008)
for 7 days starting on April 20th (2009)
for 7 days starting on April 4th (2010)
for 8 days starting on April 1st (2011)
for 7 days starting on April 14th (2012)
for 7 days starting on April 5th (2013)
for 7 days starting on April 20th (2014)
for 7 days starting on April 13th (2015)
for 7 days starting on April 4th (2016)
for 7 days starting on April 22nd (2017)
for 7 days starting on April 15th (2018)
for 8 days starting on March 31st (2019)
for 8 days starting on April 19th (2020)
for 8 days starting on April 5th (2021)
for 9 days starting on April 22nd (2022)
for 8 days starting on April 17th (2023)
for 7 days starting on April 2nd (2024)
for 8 days starting on April 21st (2025)

Dates

Founded by

Jennifer Barlow of Midlothian, Virginia in 2002

Hashtags

Sources

International Dark Sky Week, also known as National Dark-Sky Week, National Dark Sky Week, and IDSW, is observed next on Monday, April 21st, 2025. It was observed for 8 days starting on April 1st in 2003. It was observed for 8 days starting on April 19th in 2004. It was observed for 8 days on an unknown date in 2005. It was observed for 8 days starting on April 23rd in 2006. It was observed for 8 days starting on April 17th in 2007. It was observed for 7 days starting on March 29th in 2008. It was observed for 7 days starting on April 20th in 2009. It was observed for 7 days starting on April 4th in 2010. It was observed for 8 days starting on April 1st in 2011. It was observed for 7 days starting on April 14th in 2012. It was observed for 7 days starting on April 5th in 2013. It was observed for 7 days starting on April 20th in 2014. It was observed for 7 days starting on April 13th in 2015. It was observed for 7 days starting on April 4th in 2016. It was observed for 7 days starting on April 22nd in 2017. It was observed for 7 days starting on April 15th in 2018. It was observed for 8 days starting on March 31st in 2019. It was observed for 8 days starting on April 19th in 2020. It was observed for 8 days starting on April 5th in 2021. It was observed for 9 days starting on April 22nd in 2022. It was observed for 8 days starting on April 17th in 2023. It is observed for 7 days starting on April 2nd in 2024. It will be observed for 8 days starting on April 21st in 2025.

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Also on this date…

International Dark Sky Week

Also known as

National Dark-Sky Week (until 2008)

National Dark Sky Week (until 2008)

IDSW (since 2009)

Observed

for 8 days starting on April 1st (2003)

for 8 days starting on April 19th (2004)

for 8 days on an unknown date (2005)

for 8 days starting on April 23rd (2006)

for 8 days starting on April 17th (2007)

for 7 days starting on March 29th (2008)

for 7 days starting on April 20th (2009)

for 7 days starting on April 4th (2010)

for 8 days starting on April 1st (2011)

for 7 days starting on April 14th (2012)

for 7 days starting on April 5th (2013)

for 7 days starting on April 20th (2014)

for 7 days starting on April 13th (2015)

for 7 days starting on April 4th (2016)

for 7 days starting on April 22nd (2017)

for 7 days starting on April 15th (2018)

for 8 days starting on March 31st (2019)

for 8 days starting on April 19th (2020)

for 8 days starting on April 5th (2021)

for 9 days starting on April 22nd (2022)

for 8 days starting on April 17th (2023)

for 7 days starting on April 2nd (2024)

for 8 days starting on April 21st (2025)

Dates

April 22nd, 2022 to April 30th, 2022

April 17th, 2023 to April 24th, 2023

April 2nd, 2024 to April 8th, 2024

April 21st, 2025 to April 28th, 2025