The !seen command shows you when the bots think your buddy was last logged on.
Syntax: !seen username
OvEn ToAsT (12:10:17 AM): !seen oventoast
toasts aim bot 0 (12:10:21 AM): According to toastsaimbot0, oventoast is currently online.
OvEn ToAsT (12:12:08 AM): !seen twenty38
toasts aim bot 0 (12:12:11 AM): According to toastsaimbot1, twenty38 logged off at Aug 3 00:12 UTC, after being online for 0 hours, 0 minutes, and 35 seconds.