For example when a campaign is scheduled, we internally save the timestamp of it's scheduled time in Unix time format and not in the format, which is easier to read (YYYY-MM-DD hh:mm:ss). The reason is that only this format is immune to potential timezone conversion issues.
1623925680 (Unix time) = Thursday, 17 June 2021 10:28:00
After exporting the reports from our logs, you can use Excel functions to convert it into a readable format.
Assuming the Unix timestamp value is in Excel cell B5, you can use the following formula to format it in a readable date & time:
More info: https://exceljet.net/formula/convert-unix-time-stamp-to-excel-date