Here's a handy link to Gillette date codes for when you get the razor
Gillette Date Codes for Safety Razors and Blades The letter is for the year and the number (1-4) is the quarter of that year that the razor was made. For example H-3 would be 3rd quarter 1962. Cool factor aside, I've figured out that using razors older than me results in remarkable shaves (unless I do something to make it otherwise (i.e. use a dull blade, poor technique, etc.) enjoy!