Definition of productive hours for this poll: time spent on researching, designing, debugging, testing, coding, supporting, refactoring or any other technical task directly related to these which makes you get in "the zone" or totally focused on a problem.
Exclude: time spent on meetings (no matter the subject, as they can be productive for the team but not for you), managing people (only indirectly related to technical stuff), lunch time, coffee breaks and browsing the web (decompressing) and other minutes not spent on solving problems with computers.
Consider: a somewhat long time span, not just the current week or month.
...and have a happy monday :-)
PS: related poll on how people feel about their working hours at https://news.ycombinator.com/item?id=6810289