Process for joining the exported logs from Server Log into understandable format and date/time.

1) Copy all .GZ files into 1 folder on Unix environment
2) gunzip * (that would unzip all files)
3) cat ./* > logs-exported.csv (that would join all unzipped files into 1 file)

Now we are ready to go to Excel operation.
4) Open the new file with Excel
-You may delete the first two columns to make things simpler.
-Insert new column in front. Set its type as custom format cell ->> m/d/yyyy h:mm:ss
-Use the following formula for the new column
=(((LEFT(B2,(LEN(B2)-3)))/86400)+25569)-(5/24)

copy/paste this to all cells in that column matching to the corresponding cell with the unix time.

example above: B2 is the Column B and cell 2 in the column which contains the Unix format time.
The digit "3" is there to remove the last 3 digits from the unix time format.
Note that the digit "5" at the end of the Excel formula is there to put the correct time zone difference- i.e. your timezone back from GMT_00.

5) At the end of the operation you may sort the file by column A (i.e. the real date/time column).
6) Optional-> You may enable Filter per columns to easily navigate through the log messages by column content.