How to Use This Almanack

Star Almanack is designed to help you look up.

You do not need to know celestial mechanics, memorize star coordinates, or perform astronomical calculations to use this book. The mathematics has already been done. The Almanack presents the results in a form intended for someone who wants to go outside and look at the sky.

Start with the Week

The main body of Star Almanack is organized by ISO week.

An ISO week begins on Monday and ends on Sunday. Each week has a number, and each day within that week also has a number.

For example:

2026-W33-1

means:

• 2026 — the ISO week-numbering year

• W33 — week 33

• 1 — Monday

The seven days are numbered:

1. Monday

2. Tuesday

3. Wednesday

4. Thursday

5. Friday

6. Saturday

7. Sunday

Civil dates are printed alongside ISO dates, so you do not need to convert between the two systems yourself.

Read the Calendar

Each week contains a calendar showing what is happening in the sky.

Depending on the date, an entry may include:

• a zodiac day;

• a zodiac ingress;

• a Moon phase;

• a named Full Moon;

• an equinox or solstice;

• the best-visibility date of a star or other astronomical object;

• another astronomical event worth noticing.

A dash means that no event tracked by the Almanack is assigned to that date.

It does not mean that nothing is happening in the sky.

Something is always happening in the sky.

Read the Zodiac Date

Star Almanack divides the tropical zodiac into twelve equal sections of 30° each.

The zodiac symbols are:

♈︎ ♉︎ ♊︎ ♋︎ ♌︎ ♍︎ ♎︎ ♏︎ ♐︎ ♑︎ ♒︎ ♓︎

The first day after the Sun enters a new sign is numbered 1.

For example:

♈︎ (Aries) 1

is the first day of Aries.

The following days are:

♈︎ 2

♈︎ 3

and so forth until the Sun reaches the next 30° boundary.

When a zodiac symbol first appears, its name is given in parentheses. After that, the symbol can do the work.

Best Visibility

One of the central features of Star Almanack is the best-visibility date assigned to stars and other astronomical objects.

For this Almanack, an object’s best visibility occurs when it crosses the local meridian at approximately:

9:00 PM local apparent solar time

That is a deliberately chosen observing convention.

It does not mean that the object can be seen only on that date.

A star does not suddenly appear on its best-visibility date and disappear the next morning. In most cases it can be observed for weeks or months on either side of that date.

The date is a landmark.

It tells you when the object is particularly well placed in the evening sky.

Magnitude

A star’s magnitude tells you how bright it appears.

The magnitude scale runs backward: smaller numbers mean brighter objects.

In dated Almanack entries, stellar brightness is deliberately simplified into whole-number magnitude classes:

mag 1

mag 2

mag 3

mag 4

mag 5

mag 6

A mag 1 star is very bright. A mag 6 star is near the traditional naked-eye limit under a dark sky.

The underlying astronomical data may contain decimal magnitudes, but that precision is usually not useful when reading a calendar.

On constellation charts, magnitude is shown to one decimal place because there the difference between nearby stars can help you recognize the pattern.

Where Is It?

Objects are classified first by where they lie in the celestial sphere and then, where appropriate, by the season in which they are favorably placed in the evening sky.

The five declination bands used by Star Almanack are:

• Arctic

• Northern

• Tropical

• Southern

• Antarctic

A seasonal classification may therefore look like:

Northern Summer

or:

Southern Spring

The first word tells you where.

The second tells you when.

Arctic and Antarctic objects do not receive a seasonal classification.

Read a Constellation Chart

Constellation charts are intended to help you recognize patterns in the real sky.

Principal named stars are labeled with:

proper name · Greek letter · magnitude

For example:

Deneb · α · mag 1.3

The Greek letter is the star’s Bayer letter.

Only the Greek letter is printed on the chart. The full Bayer designation can be found in accompanying text or reference material when needed.

Star sizes and listed magnitudes help you compare the brightness of stars within the pattern.

The Cygnus chart is the prototype for this system.

Read the Weekly Planetary Snapshot

Each ISO week contains a snapshot of the seven classical wandering bodies:

☉ Sun

☽ Moon

☿ Mercury

♀ Venus

♂ Mars

♃ Jupiter

♄ Saturn

Their positions are calculated for:

Monday at 00:00 UTC

The position of each body is expressed as a zodiac sign, degree, and arcminute.

For example:

♑︎ 7°42′

means that the body is at 7°42′ of Capricorn.

These positions are geocentric tropical ecliptic longitudes.

You do not need to calculate them yourself.

Read the Weekly Wheel

The same seven planetary positions are plotted on the weekly circular chart.

The twelve zodiac signs form twelve equal 30° sectors around the wheel.

The First Point of Aries is fixed at the Almanack’s reference position, and zodiac longitude increases counterclockwise.

The chart has no houses and no Ascendant because it is not calculated for a particular location.

It is a picture of the week’s planetary configuration.

The table gives you the numbers.

The wheel lets you see the pattern.

Read the Moon

The Almanack records the principal lunar phases:

🌑 New Moon

🌓 First Quarter

🌕 Full Moon

🌗 Last Quarter

Full Moons may also carry traditional seasonal names.

Star Almanack uses the traditional seasonal definition of a Blue Moon: the third Full Moon in an astronomical season containing four Full Moons.

Crescent visibility is treated differently.

The Almanack may calculate the astronomical circumstances under which a young crescent could be visible, but calculation is not the same thing as an observed or religious declaration.

Our rule is:

We humbly calculate the crescent; we do not declare the month.

UTC Is the Common Clock

Astronomical events happen at instants, not separately for every time zone.

For that reason, precise event times in Star Almanack are generally given in Coordinated Universal Time:

UTC

UTC gives the entire world a common clock for describing the same astronomical event.

Your local civil date may sometimes be different.

That is not an error.

It is what happens when one sky meets many clocks and calendars.

Symbols Are Part of the Language

Star Almanack uses astronomical symbols because they allow a large amount of information to fit into a small space.

You are not expected to know them in advance.

A symbol key appears in the front matter, and symbols are identified when they are first introduced.

After a little use, something like:

☽ ♌︎ 18°

becomes easier to read than:

Moon at 18 degrees of Leo.

That is the idea.

You Can Ignore the Mathematics

Everything in Star Almanack rests on calculations that can be examined elsewhere in the book.

You do not need them to use the Almanack.

If you want to know why the 9:00 PM best-visibility rule works, how zodiac ingress is calculated, why ISO weeks behave the way they do, or how the astronomical values were validated, the mathematics and validation sections show the machinery underneath.

But when you are standing outside under a clear sky, none of that is required.

Find the week.

Find the object.

Find where to look.

Then look up.