I only have a Chemistry bottle, not the packing carton. How can I determine from the Lot number the “Best if Used By” date?

A typical Lot Number would look like this: 01204 2.  The first digit is an internal control.  The next three digits “120” indicate the Julian date of production; this Chemistry was made on the 120th day of the year, April 29th.  The fifth digit, “4”, indicates the year of production, 2004. The last digit after the space, in this case a 2, indicates that this bottle belongs to the second batch produced that day.  Air Techniques Chemistry has a one-year storage life.  So, this bottle is “Best if Used By” April 29th, 2005.