The stat command can be used to display the time a file was last accessed (atime), last modified (mtime) and last changed (ctime).

~]# stat /tmp/foo.txt
  File: /tmp/foo.txt
  Size: 7940168         Blocks: 15520      IO Block: 4096   regular file
Device: fd04h/64772d    Inode: 105729      Links: 1
Access: (0664/-rw-rw-r--)  Uid: (  409/ john.doe)   Gid: ( 2001/admins)
Context: system_u:object_r:usr_t:s0
Access: 2020-03-31 22:44:47.895474745 -0500
Modify: 2020-03-31 22:43:17.434452999 -0500
Change: 2020-03-31 22:43:17.434452999 -0500
 Birth: -

Or, the --format option can be used to display just the last accessed time (atime).

• %x = human readable
• %X = seconds since epoch

stat --format %x /tmp/foo.txt

Or just the last modified time (mtime).

• %y = human readable
• %Y = seconds since epoch

stat --format %y /tmp/foo.txt

Or just the last changed time (ctime).

• %z = human readable
• %Z = seconds since epoch

stat --format %z /tmp/foo.txt