Refined the task duration [skip hazardlib][demos]
Refined the task duration [skip hazardlib][demos]


Former-commit-id: 2633b24478257734bda5bc7d9db93763ca64515f [formerly 2633b24478257734bda5bc7d9db93763ca64515f [formerly 855dfa2ae3e2d479f717b32b42b196778eb3e712]]
Former-commit-id: 7e5833ee06cd23f1880076365eabc6be57628faa
Former-commit-id: 6074b19739816d6fff7157cc93bbb2029c895daa
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine