Calculate the difference (in hours) between two dates

Subtract the two Date objects and divide by the number of milliseconds in an hour to get the difference (in hours) between them.

const getHoursDiffBetweenDates = (dateInitial, dateFinal) =>
  (dateFinal - dateInitial) / (1000 * 3600);

// EXAMPLE
getHoursDiffBetweenDates(
  new Date('2021-04-24 10:25:00'),
  new Date('2021-04-25 10:25:00')
); // 24

Source

https://www.30secondsofcode.org/js/s/get-hours-diff-between-dates