\ifdefiningfootnotes
\DeclareFixedFootnote{\fnNightWatch}{ 
    Time during the day was counted as hours from sunrise.
    But at night the Roman system of `watches' was used: 
    \newline
    First watch: roughly 6pm to 9pm,
    \newline
    Second watch: roughly 9pm to midnight, 
    \newline
    Third watch: roughly midnight to 3am, \newline
    Fourth watch: roughly 3am to 6am, 
}
\fi