How to use EarthSky’s lunar calendar

EarthSky’s lunar calendar is a unique, beautiful poster-sized calendar printed in lush silver on deep blue, providing the phases of the moon for every day of the year, and noting each month’s new and full moons. It shows the moon waxing from new to full, and waning from full to new. It’s gorgeous. It’s the best gift ever! And it’ll help you get in touch with nature. What more could you ask? Read the six tips below and enjoy your moon calendar.

Tall blue rectangle with circles and crescents on it.
Moon phases for each day of the year on EarthSky’s lunar calendar.

Order your EarthSky lunar calendar here.

1. First, get to know your calendar. The horizontal row at the top represents months of the year. The vertical rows to the right and left give you the date. Yep. It’s just that simple.

Circles and crescents in white on blue background.
The lunar calendar shows every day in every month of 2021. Available now!

2. Enjoy the moon’s cycle. One cycle, from new moon to new moon, is called a lunar month or synodic month. The mean length of the phase cycle is 29.53059 days (29 days 12 hours 44 minutes), though in reality it can vary from about 29.3 to 29.8 days.

3. Each night, notice the moon’s phase. The phase of the moon will let you know if the moon will be out tonight, and when. At new moon: moon not visible (unless there’s a solar eclipse). At first quarter: moon lights up the evening hours, setting in the west around midnight. At full moon: moon stays out all night long. At last quarter: moon rises in the east around midnight, and can be found in the morning sky.

4. Realize that the moon is a world in space. Like Earth, it’s always half-lit by sunshine and half-engulfed in its own shadow. But the percentage of the moon’s daylight side that we see from Earth changes. The moon’s night side faces us at new moon, and its totally illuminated day side faces us at full moon. The terminator – the shadow line dividing the lunar day from the lunar night – shows you where it’s sunrise on the moon as the moon waxes from new to full. It shows you where it’s sunset on the moon as the moon wanes from full to new.

Half-lit Earth from north, and half-lit moon with divisions between dark and light sides lined up.
Phases of the moon as it revolves around the Earth. Click here to see animation.

5. Collect ’em. Hold on to your EarthSky lunar calendars, even after the year has passed. If you post them on your wall side by side, they make a very cool wave pattern. Plus … consider that the ancients discovered that 235 lunar (synodic) months almost exactly equal 19 years. That means the phases of the moon will recur – or nearly recur – on the same calendar dates 19 years from now. Woot!

6. Order your EarthSky lunar calendar today and enjoy a newfound appreciation for the lunar month and the intriguing cycle of lunar phases.

Order your EarthSky lunar calendar here.

A composite of various moon phases by EarthSky Facebook friend Jacob Baker. He wrote:
A composite of various moon phases by EarthSky Facebook friend Jacob Baker. He wrote: “This is a composite of 8 separate photos taken over the past summer showing some various phases. All shots taken with my Meade 114mm reflector, 2X Barlow, CanonT3 at Prime Focus.”

Bottom line: Here’s why you need an EarthSky lunar calendar, top tips for using it, and a place to order one. Enjoy a newfound appreciation for the lunar month and lunar phases. Live by the moon!

Order your EarthSky lunar calendar here.

Find EarthSky astronomy tools and gear at the EarthSky Store

May 25, 2020

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Bruce McClure

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