LEO Varadkar has faced social media ridicule after posting a video which shows him working in bright daylight at 5pm.

The newly-appointed Taoiseach, who on Saturday succeeded Micheál Martin as leader of the Irish government, posted a collection of the day's highlights on Twitter, soundtracked by Ian Post's On The Way.

"On Saturday, I hit the ground running as taoiseach," he remarked.

"Here's a look behind the scenes of that day."

The montage begins with the Fine Gael leader paying respects to fallen members of the Defence Forces at 9.30am.

He subsequently arrives a Government Buildings 15 minutes later, while various clips, including his nomination speech in the Dáil at 1pm, are featured along with a corresponding time.

However, in the final scene from his new quarters at Government Buildings, which includes the caption "5pm – Getting on with the job", bright light is streaming in through the office window.

Sunset in Dublin on Saturday December 17 was 4.06pm.

A large number of Twitter users highlighted the error.

People Before Profit TD Paul Murphy tweeted: "Why is it bright at 5pm outside the taoiseach's office?"

Some used humour, with one posting "There's a grand auld stretch in Dublin," while other accounts were more pointed: "Leo Varadkar has 6 advisors with total salaries of €700,000 a year yet not one could tell him it's pitch dark at 5pm."