Puck.js as power meter logger - how do you keep track of pulses per hour and day?

Hi
I have started with this example as a base to modify for my needs:
https://www.espruino.com/Smart+Meter

I am measuring time between pulses to calculate current power use. But I also want to keep track of pulses per hour and per day. I am lost at math that is used in the example to modify. I dont need an array to store, as data will be picked up but another device and stored elsewhere.
Can someone point me in the right direction/assist with javascript to detect a day/hour rollover, so that counters can be reset?
Some pseudo-code =)

var hourPulses=0
var dayPulses=0
For every pulse
   if hour > previous hour then hourPulses =0
   if day > previous day then dayPulses =0
   increment dayPulses
   increment hourPulses
   send NRF data
   loop

Something like that. I just dont know how it will work when moving into a next day.
The example in the link above somehow magically sets it into an array. But I just want one value to be sent for the current hour and day.

Mon 2021.07.12

Hi @user130485

re: 'Can someone point me in the right direction/assist with javascript to detect a day/hour rollover'

While the collection and conversion of pulses code/concept is not shown, and knowing that the Javascript Date() function constructor is based on the number of milliseconds since 1 January 1970 UTC, it would make sense just to return the current time in msec and remain using msec, then extract the hours and minutes individually as needed, rather than a more obtuse method of trying to detect rollover.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/Date

Interactive live playground:

https://www.w3schools.com/js/js_dates.asp

https://www.codesdope.com/blog/article/how-to-create-a-digital-clock-using-javascript/

I have another reading that shows current watts based on time between the pulses.
But I wanted to keep track of the total pulses for the day and actual kW use per hour. But for this I need to know when the current hour or day is over

Does the time sync happen during the code upload? Guess it would break then when doing battery replacement

ok, got it sorted