I get external data (kilowatt hours) that records data every 15 minutes.  I like looking at a year's worth of data (or more, even 2-3 years) for analysis.  I'd like to analyze the data in various ways like how much kWh is used from say 00:00-06:00 hours (unoccupied building) compared to 06:00-18:00 compared to 18:00-23:45.  I'd also like to look at the different days of the week, e.g. Saturdays and Sundays would be expected to be lower, Monday might be higher than the other weekdays as the mechanical equipment runs to get the spaces back to temperature.  Also comparing the energy use during the various months too.  Example time stamp in a single cell would be "10/31/18 13:45" (October 31 2018 at 1:45 PM).  What is the easiest way to have Excel take the time stamp and put it into the individual components, Month, Day or the week (differentiate work days from non-work days) , time of day (ability to group time into shifts per day), year (ability to define holidays too would be great).

Bob Marolt