I love deadlines...
I love deadlines. I like the whooshing sound they make as they fly by.—Douglas Adams, author, The Hitchhiker's Guide to the Galaxy
Dates are tricky things. How you interpret dates is impacted by whether you're delivering or receiving the thing you're discussing. What does Q1 mean for a release date? For the developers (who are delivering it), "Q1" means the end of the last day of the quarter. For customers, sales people, and marketers (who are waiting for delivery), "Q1" means the beginning of the first day of the quarter.
One friend says you can have either a month OR a year but not both: "It will be 'a' September but not necessarily 'this' September."
When using dates, consider how others will interpret the date and communicate accordingly.