The 2038 problem refers to the issue that will arise when 32-bit signed integers, which have been used since the 1970s to represent time, roll over and become negative values. This can cause problems with date calculations and logic in software, particularly for systems that use Unix-style 32-bit dates. MongoDB uses 64-bit dates, but users may need to review their own code to ensure they are not using 32-bit dates, which can be converted to 64-bit values. The problem is not limited to the year 2038 and can occur years earlier, depending on the date range used. To avoid potential issues, it is recommended to use 64-bit ISODates instead of 32-bit Unix time or dates.