ufs - Expand time_t support to 48 bits
http://lists.dragonflybsd.org/pipermail/commits/2019-March/718475.html [lists.dragonflybsd.org]
2019-04-24 22:42
Fix time overflow issues in the original 32-bit UFS code in two ways. First, treat the original 32-bit seconds fields as unsigned.Second, utilize the spare fields to expand these fields to 48 bits each. Retain the nanosecond-grain accuracy of the nsec fields.
source: Dfly