1. What is the Moon Phase Calculator?

The Birthday Moon Phase Calculator determines the phase of the moon on any given date using astronomical calculations. It provides both the phase angle (0-360°) and the common name of the moon phase.

2. How Does the Calculator Work?

The calculator uses the following equation:

Where:

• \( JD \) — Julian Date of the birth date
• 2451545 — Julian Date reference point (January 1, 2000)
• 29.53058867 — Length of a synodic month in days

Explanation: The equation calculates the moon's position in its cycle relative to the sun, expressed as an angle from 0° to 360°.

3. Importance of Moon Phase Calculation

Details: Knowing the moon phase on your birthday can be interesting for astrological purposes, personal curiosity, or understanding tidal patterns on that date.

4. Using the Calculator

Tips: Simply enter your birth date and the calculator will determine the moon phase at that time. The result shows both the phase angle and common name.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: The calculation is accurate to within a few degrees for dates between 1900-2100.

Q2: What do the phase angles mean?
A: 0° = New Moon, 90° = First Quarter, 180° = Full Moon, 270° = Last Quarter.

Q3: Why use Julian Date?
A: Julian Dates provide a continuous count of days, making astronomical calculations simpler.

Q4: Can I calculate moon phases for future dates?
A: Yes, the calculator works for any date between 1900-2100.

Q5: What's the difference between synodic and sidereal month?
A: A synodic month (29.53 days) is the time between identical phases, while a sidereal month (27.32 days) is the moon's orbit relative to stars.