The MCA (Anvil) file format has the following data in the headers:

• Cluster 0: Location and size of chunk data.
• Cluster 1: Date stamps of last modification for each chunk as 32-bit integers

These 32-bit integers are expressed as the number of seconds since January 1, 1970, and these file modification times are showing their age. (Recent files would have values around 5E 00 00 00 hex.)

These 32-bit integers are not currently a problem, but they are deprecated. They will be problematic when they reach 80 00 00 00 hex in January, 2038. They could be treated as negative numbers and any comparisons would fail.