The Champions League is back, and if your commute home from work is more than 45 minutes, you might miss some of it. That is if you're in the UK, of course.

Arsenal are among the teams playing in the 5.45pm BST slot in the opening week of the competition. The Londoners play at Athletic Club in one of six early kick-offs in this week's schedule.

And though it's been the case for a few years, Champions League football on Thursdays still feels new enough to be unusual.

Here's a guide to this week's Champions League kick-off times, and why games are now played on Thursdays.

UEFA, European football's governing body, introduced the 5.45pm BST kick-off slot in 2021 for its club competitions, the Champions League, Europa League and the then-new Conference League.

Different kick-off times were first introduced in 2018, with two matches on Tuesdays and Wednesdays starting at 5:55pm BST. Until 2021, there were no 5.45pm BST (12.45pm ET) kick-offs. Previously, some matches in Eastern Europe kicked off at 5pm BST (12pm ET), such as Zenit St Petersburg's home games in the 2011-12 Champions League.

Staggering kick-off times allows television viewers to watch more games and means fewer overlaps for broadcasters, creating more revenue for them and clubs.

It also helps make games more timezone-friendly for global audiences. In California, for example, the early kick-off would be the start of the working day, but those in New York could sneak in at least 60 minutes if they time their lunch break correctly.

This year, the Champions League final will be played three hours earlier, at 5pm BST (12pm ET) instead of 8pm BST (3pm ET), with UEFA citing a "more accessible broadcasting window", "improved access to public transport", and a "safer, more convenient journey back from the stadium".

The final is played on a Saturday, meaning many don't have to take work considerations into account.

The standard working day in the United Kingdom is 9am to 5pm, so a 5.45pm kick-off cuts it fine for fans going to the stadium from work, especially if they don't live close to their home stadium. Even commuters hoping to watch on TV could miss kick-off.

Many fans like to catch up with others before a match, at the pub, for example, so the early kick-offs leave little time for socialising before the game.

It also means travelling to games has to be done during peak hours for traffic and public transport, although on the flip side, it does allow supporters to get home earlier and be well rested for the next working day.

While no one has been outspoken about the new kick-off times so far this season, former Liverpool manager Jurgen Klopp was regularly irked by his team playing Premier League games at 12:30pm BST on Saturdays following international breaks, calling it "a joke" in 2023.

As part of the new format introduced last season, each of the three UEFA competitions has its own exclusive matchweek without fixtures from the other two competitions.

For the Champions League, this is the opening week played on September 16, 17, and 18, which is when the Thursday fixtures will take place.

The Europa League's exclusive week will be played on September 24-25, and on December 18, there will be 18 Conference League games taking place.

After all, the new format has increased the number of teams from 32 to 36, and with each side playing at least eight games in the league stage (there were previously six ties in the group stage), the number of matches has increased from 125 to 189.

Thursday nights used to be exclusively for the Europa League, European football's second-tier competition, before the introduction of the Conference League and then the new Champions League format.

English teams have played 71 games across the UEFA Conference, Europa, and Champions League that kick off at 5:45pm BST.

With 35 wins, they have won just under half of those. Fourteen games have been draws and 22 ended in losses.

The best performers in the early kick-off have been Chelsea, who have won six games, drawn one, and lost one.

While Newcastle United are yet to win an early European tie, losing against Borussia Dortmund and drawing with Milan in the 2023-2024 Champions League, they will look for a first win in an early kick-off away at Belgian champions Union Saint-Gilloise on October 1.

This year, there will be five occasions English sides play at 5:45pm in the group phase, with those games involving Arsenal twice, Chelsea, Newcastle and Manchester City.

Champions League early kick-offs: Why are they happening and is it a good idea?