#timezone #time #solar #astrology #local-time #vedic

bin+lib solar_time

A library for calculating solar time as per vedic astorlogy principles

3 releases

0.1.4 Sep 11, 2024
0.1.3 Sep 11, 2024
0.1.2 Sep 11, 2024

#166 in Date and time


Used in aztro_core

MIT license

33KB
482 lines

Detailed Problem Description:

In Vedic astrology, the accuracy of birth time is crucial for precise calculations and interpretations. However, the time recorded on a person's birth certificate or birth record is typically based on the local time zone of the birthplace, which may not accurately reflect the true solar time at that location. Our goal is to develop a system that can convert this recorded local time to the true solar time for more accurate astrological calculations.

Key Considerations:

  1. Local Recorded Time: This is the time noted on the birth certificate or birth record. It's based on the official time zone of the location.

  2. Time Zone Offset: Each location has an official time zone offset from UTC (Coordinated Universal Time). For example, India is UTC+5:30.

  3. Longitude Effect: The sun moves across the sky at a rate of 15 degrees per hour (360° in 24 hours). This means that for every degree of longitude, there's a 4-minute difference in solar time.

  4. Equation of Time: Due to the elliptical orbit of the Earth and its axial tilt, there's a variation between mean solar time and apparent solar time. This variation changes throughout the year.

  5. Date of Birth: The equation of time varies based on the day of the year, so the birth date is crucial for accurate calculations.

Problem-Solving Steps:

  1. Input Gathering:

    • Birth date (year, month, day)
    • Birth time (hours, minutes, seconds)
    • Birth location (latitude, longitude)
    • Time zone offset of the birth location
  2. Convert Local Time to UTC:

    • Subtract the time zone offset from the local time to get UTC time.
  3. Calculate Solar Time: a. Determine the day of the year for the birth date. b. Calculate the equation of time for that day. c. Calculate the longitude correction:

    • Determine the time difference based on the longitude of the birthplace relative to the central meridian of its time zone. d. Apply both corrections to the UTC time to get the local solar time.
  4. Compare and Provide Results:

    • Show the original local time (as recorded on the birth certificate).
    • Show the calculated true solar time.
    • Display the difference between the two.

Example Scenario: Let's say a person was born in Calicut, India (11.2588° N, 75.7804° E) on September 11, 2024, at 3:30 PM local time.

  1. Input:

    • Date: 2024-09-11
    • Local Time: 15:30:00
    • Location: Calicut (11.2588° N, 75.7804° E)
    • Time Zone: UTC+5:30 (India Standard Time)
  2. Convert to UTC: 15:30 - 5:30 = 10:00 UTC

  3. Calculate Solar Time: a. Day of year: 255 b. Calculate equation of time for Sept 11 c. Longitude correction: Calicut is 75.7804° E, IST is based on 82.5° E Difference: 82.5° - 75.7804° = 6.7196° Time correction: 6.7196° * 4 minutes = 26.88 minutes d. Apply corrections to UTC time

  4. Results:

    • Original Local Time: 15:30:00
    • Calculated Solar Time: [Result of step 3]
    • Difference: [Calculated difference]

No runtime deps