@17saiiqb https://github.com/YR/MMM-YrNow/blob/master/MMM-YrNow.js#L57
and https://github.com/YR/MMM-YrNow/blob/master/MMM-YrNow.js#L62 use arrow functions, which could be replaced with normal functions as the scope isn’t used in the function anyways.
https://github.com/YR/MMM-YrNow/blob/master/printf.js#L14
return String(str).replace(RE_PRINTF, function(token) {
not sure if … was also introduced in es6 or before https://github.com/YR/MMM-YrNow/blob/master/printf.js#L10