Hey there,
Just a quick share as I would have been happy to come across such Zap.
I made a quick Zapier Zap which automatically create a Google Calendar event upon creating a task WITH due hour in Asana inside a given project.
You may also add / remove hours according to your timezone difference.
It should be straight forward.
The ZAP only works upon a new tasks creation and can be modified upon task updates.
Hope it will be useful for some.
Great, can I add it to my list iDO Tools - Improve Asana with our tools and automations ?
Thanks for sharing @Vincent_Royant! 
For sure, no worries at all.
Hello! Does the event still appear on the google calendar even when the task is completed? That’s the issue I’m having right now.
Yes, it would remain in the Google Calendar. I’m not sure there is an easy way to achieve what you would like. I believe the only way would be a custom program pulling out Tasks from Asana API and working with the Google Calendar API