This is the most common system for newer Godin, Seagull, and Simon & Patrick models. First 2 digits: The production year. 3rd & 4th digits: The production week. 5th digit: The production day (1=Monday, 2=Tuesday, etc.).
The remaining digits follow a similar week/day/rank logic to the 8-digit system but without the first "decade" digit. :
Godin has used several formats over the decades. Below is the for instruments built from the mid-1990s onward.
The reliability of a "lookup" depends heavily on which era your guitar belongs to: Serial Length Primary Era Lookup Reliability
The number of guitars built during that specific week.