timestamp(14) - phpMan

BSON::Timestamp (3pm) - BSON type wrapper for timestamps
MongoDB::Timestamp (3pm) - (DEPRECATED) Replication timestamp type
pam_timestamp (8)    - Authenticate using cached successful authentication at...
pam_timestamp_check (8) - Check to see if the default timestamp is valid
sg_timestamp (8)     - report or set timestamp on SCSI device
sudoers_timestamp (5) - Sudoers Time Stamp Format
tai64n (8)           - puts a precise timestamp on each line.
tai64nlocal (8)      - converts precise TAI64N timestamps to a human-readable...
touch (1)            - change file timestamps