Yes - as Sanmeet say, if you have the I.T. resources available, then exporting a data feed from Adobes UI (if you are an Admin) into a data lake / AWS / AZURE environment is the smartest move, but if this this not already setup in your organisation it would be a large amount of work. If you were to request a datafeed straight from Adobe Analytics there is a field in the data feed called "hit_time_gmt" which Adobe derive from Unix time themselves. However what you need to remember is that because this approach would require all columns to show all hits, you will end up with a file that is over 600 columns in width, so again not a problem if your company has this already setup but not advisable if this is a one off question.
Unix time only has one time zone and would not cause the issue Sanmeet suggests as your tag manager would be doing the calculation, not a calculation based on the users local time. However what his point does raise is that if you have one site that is used all throughout the world you may find it hard to track patterns by country unless you overlay Countries in your export - which again will make your data warehouse / API call very large.
Best would be to request for a data feed from the client care.
you can do all kind of implementations but bear in mind that these would be client side values and would send 'time' data based on the time value of the visitor. If the site spans across multiple time zones that this data can become difficult to analyze.
As far as i can understand the business objective, i would the data feed approach instead of opting for any new session based tracking
If I needed to do this I would add an EVAR that is populated with Unix time from DTM/GTM/Tealium etc on every hit.
I would then let this run for around 2 weeks to build up some data, then run a data warehouse export of evarXX (unix time stamp) and evarXX instances against it. Ideally I would then use SQL to analyse this if you are trying to see if it changes by time of day, however if you are limited to excel tools you can only really analyse 1 day at a time.