How can date/time format of Yesod logger be configured?

I have a Haskell Yesod webserver which works perfectly, and logs perfectly¹ !

postFailed :: String -> String -> Handler Value
postFailed errorMsg _filename = do
    $logInfoS "(Parser)" (Data.Text.pack errorMsg)
    returnJson (Error "FAILED" errorMsg _filename)

How can I control date/time format? removal of source code loc @(main:Main ...), etc.?

20/Oct/2024:13:12:39 +0000 [Info#(Parser)] Error[< ... omitted ... >] @(main:Main src/Main.hs:76:6)

When I look at the docs, I can't find anything related there.

¹ The complete code is here

The logging in general is configured via the makeLogger method of your Yesod instance, which you can override. This is defaultMakeLogger by default, which in turn is defined as

defaultMakeLogger :: IO Logger
defaultMakeLogger = do
    loggerSet' <- newStdoutLoggerSet defaultBufSize
    (getter, _) <- clockDateCacher
    return $! Logger loggerSet' getter

This getter here is simply a IO ByteString that provides the current datetime already formatted, so that's what you'd replace if you want a different format.

You can use newTimeCache from fast-logger for this purpose, that has the right signature and lets you pass in a time format in strftime format. Or you can put in anything else you like, as long as it's a IO ByteString that returns the current time formatted however you like.