From the GEE 2020 Vol2 - May 2019 newsletter:
Abstract submission deadline is extended! New date: May 31, 2019
After subscribing to the conference platform, please submit your abstract by e-mail to email@example.com until May 31, 2019.
You can find the guidelines for abstract submission here and other key dates here.
You can access the conference platform here.
Check out the conference venue, the highly acclaimed Acropolis Museum!