Elon Musk is spending New Year's Eve at Tesla's California factory to help deliver vehicles in the final hours of 2019

• Elon Musk says he will be working at Tesla's Fremont, California, factory on New Year's Eve to help Tesla meet its vehicle delivery goals.
• In a tweet posted Monday, Musk said that he would be spending the last work hours of 2019 at the production facility.
• This sort of behavior is nothing new for Musk, who has worked on at least his past 2 birthdays. He also claims to work 120 hours every week.
• Visit Business Insider's homepage for more stories.

As 2019 draws to a close, Tesla CEO Elon Musk plans to spend the day much as he has spent many others: at work.

In a tweet posted Monday, the Tesla cofounder said he's heading to Tesla's factory in Fremont, California on New Year's Eve "to help with vehicle deliveries."

It was posted in response to somebody who suggested he might spend the day at a SpaceX facility in Boca Chica, Texas.

Musk didn't specify whether he intends to work a normal day in Fremont, or pull one of the extra-long work sessions for which he is famous.

Tesla traditionally has an extra-busy period towards the end of each quarter in which it rushes to deliver vehicles in time for inclusion in that quarter's performance statistics.

Musk has also spoken often of working at unconventional times of the year, including on his own birthday.

In June this year, the 48-year-old was asked on Twitter how he planned to spend his birthday. He replied that he planned to spend it working on "global logistics," which is also linked to Tesla vehicle deliveries.

The picture Musk painted of his 47th birthday was bleaker still: in an interview with The New York Times, Musk said he spent the whole day alone working in Tesla's offices, with "no friends."

Though these birthday workdays could be viewed as publicity stunts, they seem to form part of a genuine, deep-seated workaholism on Musk's part.

Earlier this year, Musk claimed to work 120 hours per week and said that his 2018 schedule aged him by 5 years.

Tesla delivered 97,000 vehicles in the third quarter of 2019 - which, despite falling short of some analyst expectations, was a record for the firm.

It has said it expects to break its vehicle delivery record again this quarter, which would go some way to explaining Musk's end-of-year workday.

Musk will also be keeping one eye on China after Tesla delivered its first vehicles in the country on Monday.

Fifteen Tesla employees are set to receive units of its China-made Model 3 after they were delivered at its Shanghai "Gigafactory."