How frequently does the importrange function refresh and reload the source data?
Best Answer
When closed
Never.Spreadsheets update external api only onOpen(). But there is no documentation and this may change in the future.
When open, 30 minutes
Functions that pull data from outside the spreadsheet recalculate at the following times:
ImportRange: 30 minutes
ImportHtml, ImportFeed, ImportData, ImportXml: 1 hour
GoogleFinance: may be delayed up to 20 minutes
Opening the spreadsheet refreshes all the functions.