We sync the SecureDrop release dates to be a few days after the Tails release. So, for instance, the SecureDrop version 0.8.0 is scheduled July 3rd and the Tails version 3.8 is scheduled June 26th, a week before.
I dont’ recall why the SecureDrop version 0.7.0 was scheduled May 8th which turns out to be one day before the Tails version 3.7 was released. Was it because the release date of Tails 3.7 was changed? Or another reason?