I still remember the 2010 Event (Eyjafjallajökull) where airtravel was greatly impacted by it for a whole week at least.
The disruptions started over an initial period of six days in April 2010. Additional localised disruption continued into May 2010, and eruptive activity persisted until June 2010. The eruption was declared officially over in October 2010, after 3 months of inactivity, when snow on the glacier did not melt. From 14 to 20 April, ash from the volcanic eruption covered large areas of Northern Europe. About 20 countries closed their airspace to commercial jet traffic and it affected approximately 10 million travellers.
Composite map of the volcanic ash cloud spanning 14–25 April 2010
