What is the schedule for science runs of aLIGO (and VIRGO)?
There is no set date due to the complexity of the machines and their upgrades but this is the closest you will get to an answer:


  O1 is planned to last for four months, closing mid-January 2016. Then work will start on upgrading the instruments for our second observing run, which is called O2; those upgrades will be informed by what we have learned about the instruments during O1. O2 will start in 2016 and last around six months. Hopefully, around this time Advanced LIGO will be joined by Advanced Virgo.


They have no fixed date for the second observing run (O2) but it should be up an running later this year (my guess would be June-July time).