No timestamps in fetchmail log

I am running fetchmail 6.6.62 on Raspberry Pi OS. The log is set to a logfile. The problem is, that the logfile does not have timestamps when a mail is retrieved. How can I set fetchmail to record the time the message is retrieved? The fetchmailrc file is the following:

set postmaster "foobar"
set bouncemail
set no spambounce
set softbounce
set properties ""
set daemon 10
set logfile /home/foobar/fetchmail.log
poll imap.gmail.com with proto IMAP
       user 'foo@gmail.com' there with password 'XXX' is 'foobar' here options fetchall nokeep idle ssl sslcertck

and the log looks like this:

fetchmail: 1 message for foo@gmail.com at imap.gmail.com.
fetchmail: reading message foo@gmail.com@imap.gmail.com:1 of 1 (4901 header octets) (741 body octets) flushed
fetchmail: 1 message for foo@gmail.com at imap.gmail.com.
fetchmail: reading message foo@gmail.com@imap.gmail.com:1 of 1 (5135 header octets) (1586 body octets) flushed