This plugin captures all chat lines and commands entered and stores them in matching log files, one per day. You're then free to access your log files, through FTP or otherwise, to see what was logged on any given day.
No configuration, no commands, no permissions; it runs quietly in the background.
Output
Chat File: plugins/IOLogger/logs/chat/DATE.txt
00:00:45 | Doctacosa@world(248,65,65): [Doctacosa joined]
00:01:03 | Doctacosa@world(248,65,64): Hello world!
00:02:42 | Doctacosa@world(2598,59,-1959): [Doctacosa left]
Commands File: plugins/IOLogger/logs/commands/DATE.txt
00:01:20 | Doctacosa@world(350,70,72): /time
Why is this plugin reliable?
I use all of my plugins on my own servers, and I like my plugins to be stable, reliable and low maintenance. Breaks on version upgrades are not expected, but should they happen, they will be quickly fixed.
Support my work
If you enjoy my work, I welcome sponsors! I've been running Minecraft servers since 2011, developed several plugins and tools for server owners, and I'm now working my way through releasing many of them. Your support would go a long way toward encouraging me to put more time and effort into this, plus fix any issues that might be discovered over time!