Prints out each merge in the tree, combines it with the age of the last commit on each branch, and reverse sorts it.

commit-waiting-time.sh

#!/bin/bash
export prefix="origin/release"
export curr="$prefix/2.21"
export time="091900002018"
for repo in $(echo */); do
  pushd $repo > /dev/null
  if [ $(git branch -r | grep -c $curr) -ne 0 ]; then
    export curr_line=$(($(git branch -r | grep "$prefix/[012]" | sort -r | grep -n $curr | cut -f1 -d':') + 1))
    export prev=$(git branch -r | grep "$prefix/[012]" | sort -r | head -n $curr_line | tail -n 1 | cut -f3 -d' ')
    for commit in $(git log $prev..$curr --pretty=format:"%ct %d" | tail -n +1 | grep '(' | uniq -is 10 | cut -f1 -d' '); do
      echo "(" $(date -j $time +%s) - $commit ")" / 86400 | bc;
    done
  fi
  popd > /dev/null
done