One thing I've noticed is that the time stamp in the logs appears to be based on US time. I can see the following in the workings of the code.gs - does this need to be changed if I'm in the UK? If so, how? Grateful for any help folks.
function FormatDate(val){return Utilities.formatDate(val, SpreadsheetApp.getActive().getSpreadsheetTimeZone(), "dd/MM/YYYY");}
function FormatDayDate(val) {return (isValidDate(val)) ? Utilities.formatDate(val, SpreadsheetApp.getActive().getSpreadsheetTimeZone(), "E dd/MM/YYYY") : val;}
function FormatDateTime(val){return Utilities.formatDate(val, SpreadsheetApp.getActive().getSpreadsheetTimeZone(), "dd/MM/YYYY hh:mm:ss a");}
EDIT: Just had to go into Files>Settings and change Locale and Time Zone