How Many Days Until Summer 2021? October 16, 2020June 7, 2016 by Chris Robbins2021 Summer SolsticeSunday, June 20 at 11:32 pm EDT Duration of Summer 2021: 93 days, 15 hours, 49 minutesSimilar Posts:Days Until Winter 2020 CountdownHow Many Days Until Spring 2021?How Many Days Until Fall 2021?