Since 2000 the tournament has culminated in March, with Ross County and Hibernian meeting in this season's final at Hampden next month.
Plans for a competition reformat were announced last year, beginning in July and with group stages introduced.
It has also been confirmed that the planned three-week winter break for the Premiership will start immediately after the new-year fixture round.
Top-flight teams will return to action in the Scottish Cup fourth round on the weekend of 21 January.
"The Scottish League Cup semi-finals and final will again be contested before the end of the year, which we know is something a large number of supporters and stakeholders, including the media, were very keen on," said Scottish Professional Football League chief executive Neil Doncaster.
The Scottish League Cup final will return to November from next season.