Specify the snapshot date and time. All users logged in at the snapshot date and time will be reported. This may be used with the -f option to derive the results from stored wtmp files. When this argument is provided, all other options except for -f and -n are ignored. The argument should be in the form .Sm off [[CCYY]] [MM DD] hh mm [.SS] .Sm on where each pair of letters represents the following:
CC
The first two digits of the year (the century).
YY
The second two digits of the year. If YY is specified, but CC is not, a value for YY between 69 and 99 results in a CC value of 19. Otherwise, a CC value of 20 is used.
MM
Month of the year, from 1 to 12.
DD
Day of the month, from 1 to 31.
hh
Hour of the day, from 0 to 23.
mm
Minute of the hour, from 0 to 59.
SS
Second of the minute, from 0 to 61.
If the CC and YY letter pairs are not specified, the values default to the current year. If the SS letter pair is not specified, the value defaults to 0.
-f file
Read the file file instead of the default, /var/log/wtmp.
-h host
Host names may be names or internet numbers.
-n maxrec
Limit the report to maxrec lines.
-s
Report the duration of the login session in seconds, instead of the default days, hours and minutes.
-t tty
Specify the tty. Tty names may be given fully or abbreviated, for example, ""last -t 03"" is equivalent to ""last -t tty03"".
-w
Widen the duration field to show seconds, as well as the default days, hours and minutes.
-y
Report the year in the session start time.
If multiple arguments are given, and a snapshot time is not specified, the information which applies to any of the arguments is printed, e.g., ""last root -t console"" would list all of "root s" sessions as well as all sessions on the console terminal. If no users, hostnames or terminals are specified, last prints a record of all logins and logouts.
The pseudo-user reboot logs in at reboots of the system, thus "last reboot" will give an indication of mean time between reboot.
If last is interrupted, it indicates to what date the search has progressed. If interrupted with a quit signal last indicates how far the search has progressed and then continues.