The lot number is assigned based on the date of production, which is represented in the Julian date format using seven digits. The Julian date format is a chronological system that represents dates as a count of the number of days elapsed since January 1, 4713 BCE.

In the context of lot numbers, the first three digits of the Julian date represent the day of the year, while the remaining four digits represent the year. For example, January 1st would be represented as “001” in the Julian date format, while December 31st would be represented as “365” in a non-leap year.

The last digit of the lot number typically indicates the number of finished products that were produced on that day. For example, if a company produced 500 units on February 22nd, 2023, the lot number for that batch of products might be “2305322-5”. This indicates that the batch was produced on the 322nd day of the year 2023, and that it was the fifth batch produced on that day.