T-3 head light date code

[freddy]

[ QUOTE ]
What's it's diameter?
That third line is the date code.
First character denotes the month.
second year..
third day of month.
I can only make out the 6,so most likely 1966.Can you make out the third line any better?

[/ QUOTE ] 6012 is a 7" round(large). I thought the bulbs with lines in the script are 68-71 so how could this be a 66? I have a 4002 small round low beam with lines that the ink stamp date line is clear and reads 15 0 8 so it must be day-year-month.