WRT to your monitoring timestamp concerns, I assume that this is something you set up through Webmin? TBH, I'm not particularly familiar with Webmin usage. We do package it and I do basic pre-release testing. But I almost never use it personally - I'm more of a commandline sort of guy... :)

FWIW, under the hood (like most Linux GUI tools) Webmin generally leverages existing commandline tools. So if you can provide a little more context to how you set it up, then I can try to reproduce it and hopefully work out what it's really doing under the covers (and hence why it's using the type of timestamps it is).

I did a quick google and a couple of Webmin docs pages came up (here and here) but neither of them seemed particularly useful for your immediate issue.

It may also be worth asking about it on the Webmin forums too? Whilst we package it and do a few things differently (e.g. run it behind Stunnel), the bulk of it uses default upstream (i.e. Webmin dev) settings. If we change the default timestamps in monitor emails, it's certainly not intentional. Most likely it is something that is configurable, which we're not adjusting (but could if we knew how).

Another possibility is that there is a missing dependency that provides the info in a "nicer" way and without that installed, it falls back to the best it can? Or perhaps it's a bug or oversight by the Webmin devs?

With regards to the ProFTPD issue, I'm assuming that you have installed both proftpd and the proftpd Webmin module already? (Almost certainly you've got the Webmin module I guess...). Assuming so, then I'm not completely sure. I do know that some modules require service restart to apply updated settings (and as proftpd is a daemon, my guess is that's one of those). In those cases (at least in the old theme we used to ship with), there is often no "apply" button, you have to stop/start/restart the service to apply updated settings - for which there usually are buttons supplied. Some other services reload their config automatically, so simply changing it is sufficient. Although again, it may be an oversight of the Webmin devs, or in that case, more likely the Authentic theme devs.

With regards to updates. The 1.890 changelog entry doesn't note anything specific about email timestamps, so I'm not even sure an update would solve it. Having said that, it does state that it's got better handling for newer postfix version (postfix is the default MTA we use). It also mentions that it now includes support for Debian 9 (the basis of TurnKey). So perhaps there is something in that that would improve things?

I'll try to update our packages sometime soon (especially if you can confirm that the newer version provides the fixes you are after). But in the meantime you could try downloading and installing the deb file, which should give you the latest version.

You can try doing that via Webmin, but personally, I'd just do it via commandline. Either way, I'd recommend testing on a throwaway VM before you do it on a production server (or any server that matters really)! Here's the commandline install:

wget https://sourceforge.net/projects/webadmin/files/webmin/1.890/webmin_1.890_all.deb
dpkg -i webmin_1.890_all.deb
service restart webmin

FWIW, the main reason why we package it ourselves, is because we try to keep things minimalist. By default, it installs with all modules. The only other otpion, is to install with pretty much none. By packaging it as we do, we can ship the minimal set of modules for each appliance, and non of the additional ones which would be irrelevant. But the additional modules are still available if anyone wants/needs them.