I have a column in Sheet1 that contains dates in format DD/MM/YYYY, like this:12/10/201528/09/201528/09/201528/09/201528/09/201528/09/201528/09/201526/10/201526/10/201526/10/201526/10/201512/10/201512/10/201512/10/2015And I'm trying to select with a QUERY all the entries that are less than 15/10/2015. I know there are other methods but I need to use SQL syntax (this is a simplified version of the big formula and I need SQL to make the other bits work).=QUERY(IMPORTRANGE(BLABLABLA, Sheet1!A2:A),SELECT * WHERE Col1 <= '15/10/2015')But the query completes with an empty response. I even tried to use the MM-DD-YYYY format in the QUERY or just 2016still an empty response.My spreadsheets locale is UK.
Using query command with dates
google spreadsheets
Replace  WHERE Col1 <= '15/10/2015'with WHERE Col1 <= date '2015-10-15'That is, you need to provide date in ISO format and precede it with the keyword date so that it is parsed accordingly.