Grav Mass Day 2017: When Is Grav Mass Day? 🗓

When is Grav Mass Day 2017? This year Grav Mass Day is celebrated on a Monday, December 25, 2017. In 2018, Grav Mass Day is on Tuesday, December 25, 2018.

Grav-Mass Day is an unofficial holiday celebrated annually on December 25, the birth anniversary of English physicist and mathematician Isaac Newton.

A play on Christmas, the holiday is a celebration of science and reason. It is also considered to be a secular alternative to the Christian holiday.

Countdown to Grav Mass Day date is below, plus holiday history, celebration info, facts and holiday details.

When is Grav Mass Day 2017? This year Grav Mass Day is on Monday, December 25, 2017.


Grav-Mass refers to the Gravitational Constant and Mass, two key components of Newton’s law of universal gravitation.

Below you will find all the details for Grav Mass Day 2017 including, are banks open, is there mail delivery and related holiday information.

Is Grav Mass Day a federal holiday?

No, Grav Mass Day is not a federal holiday. There are ten annual US federal holidays on the calendar designated by the United States Congress. The following federal holidays are established by law:

  • New Year’s Day
  • Birthday of Martin Luther King, Jr. (Third Monday in January).
  • Washington’s Birthday (Third Monday in February)
  • Memorial Day (Last Monday in May)
  • Independence Day (July 4)
  • Labor Day (First Monday in September)
  • Columbus Day (Second Monday in October)
  • Veterans Day (November 11)
  • Thanksgiving Day (Fourth Thursday in November)
  • Christmas Day (December 25)

Is Grav Mass Day a national holiday?

Grav Mass Day is not a national holiday. Unlike many other countries, there are no ‘national holidays’ in the United States because Congress only has constitutional authority to create holidays for federal institutions. Most federal holidays are also observered as state holidays.

Is Grav Mass Day a paid holiday?

No, Grav Mass Day is not a paid holiday. The Fair Labor Standards Act (FLSA) does not require payment for time not worked, such as vacations or holidays (federal or otherwise).

Does the mail run on Grav Mass Day?

Yes, there will be mail delivery on Grav Mass Day. All post offices and federal offices of any kind will be open for the holiday, which means businesses and homes will receive mail. This also counts USPS and Fedex packages. See holiday schedule on USPS and Fedex. The only time mail is not being delivered is on federal holidays, which are listed above.

Are banks open on Grav Mass Day?

Grav Mass Day is a Fun holiday, which means all federal offices, courts and most banks will be open. While most banks are open, some banks can operate on their own schedules, so it may be best to check with your local branches. U.S. stock and bond markets like the New York Stock Exchange and NASDAQ will be open. Grocery stores and malls are reportedly open.

If your bank is closed, it is still possible to conduct general banking transactions via ATM, online banking or your mobile phone. Apps and websites are running though not all normal functions may be accessed for the holiday.

Are stores open on Grav Mass Day?

On Grav Mass Day, most stores, restaurants, shopping centers, and malls are open. There are no holidays on which all businesses are closed by law. However, some stores may have shortened or extended holiday hours for the day. Stores may be operating on holiday schedule with limited or reduced hours of operation. Some businesses may be closed on in order to give their employees the day off. For restaurants, stores and other establishments specific to your area, you will have to check with the individual business.

Shop Grav Mass Day Gifts on Amazon

Grav Mass Day 2017

Holiday: Grav Mass Day
Date: December 25, 2017
Weekday: Monday
Holiday Type: Fun
Grav Mass Day 2018: Tuesday, December 25, 2018
Grav Mass Day 2019: Wednesday, December 25, 2019
Grav Mass Day 2020: Friday, December 25, 2020

Fun Holiday Fact

Did you know …that technically we should be celebrating Newton’s birthday on January 4? This is because when he was born on December 25, 1642, the Julian Calendar was still in effect in England.

How To Celebrate Grav Mass Day

Celebrate the life and times of Isaac Newton by sharing scientific ideas and discoveries with each other.

Stallman, the inventor of the holiday, recommends decorating one’s Christmas tree with apples – the fruit that Newton credited for giving him the idea about gravitation.

Make science and physics related parodies of Christmas carols and sing them.

Greet people by saying “Merry Grav-Mass to you”, and respond by saying “may the Force be proportional to your acceleration”. These greetings come from Hogan’s short story.

Send Grav-Mass Day greeting cards that say “Reasons Greetings to you”.

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