The First two numbers are the week of the year, The Second two numbers are the year made. They tried to sell me a six year old ( new ) tire today. I think this is on all tires.
That picture shows 3906 which would be 39th week of 2006? I think the tire identifier might be an 8 digit number if manufactured in this decade with the last 4 digits identifying week and year of mfgr? I assume the H2MM is part of the above example?