Checked several other Stack Overflow Questions, searched for a while through all unknown date format questions, none I found look like this. I need to deal with this type of date time format in Javascript, which Google Sheets and LibreOffice Calc both are able to recognize and parse as 5/24/2023 10:00 for this example.
45070.416666666664 <- what date time format is this?
In GSheets (as others), change format to date.
In app script, use
function myFunction() {
const sh = SpreadsheetApp.getActiveSheet()
const value = sh.getRange('C1').getValue()
console.log (Utilities.formatDate(value, Session.getScriptTimeZone(), "MM/dd/yyyy HH:mm"))
}