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Dharma Open School
Tools

Vaiṣṇava calendar

The year, with its festivals and fasts, calculated for where you are. Built on established astronomical libraries, never estimated.

Source boundary visible4 active units

Vaiṣṇava calendar laboratory

Calculate the sky first; apply a named and verified observance rule-set second.

The school developed these teaching notes. They are not presented as Aniruddha Dāsa's authored commentary. The source trail and limits remain visible for human review.

Learners moving from source reading to practice and teaching
Learn visibly: retrieve · make · discuss · teach · return
Learning outcomes
  • Create something that can be inspected
  • Keep source, interpretation and uncertainty visible
  • Use teach-back as evidence of understanding
Saved on this device0%
Course sequence

Make evidence at every step

Teach-back

Explain the result to another person without looking, then reopen the source and correct the explanation visibly.

Completion evidence

An astronomical snapshot plus temple-calendar comparison.

Research and source trail
Read the complete teaching notesOpen
Full lesson readerFormative assessment included

Read less. Do more. Show what changed.

Every unit below contains an explanation, a worked model, immediate practice, a source boundary and a check for understanding. The familiar “learning pyramid” percentages are not used; its useful active modes are rebuilt here with retrieval, spacing, feedback and learner choice.

Encounter
Retrieve
Demonstrate
Discuss
Practise
Teach
Choose a lesson

All 4 lessons are complete.

Lesson 1 of 4

Set inputs

Record date, time, timezone, latitude and longitude.

1 · Understand the move

A trustworthy calculation can be reproduced. It records date, local time, timezone, latitude, longitude, unit and software version.

In this lesson, the concrete target is A reproducible input record. Begin by defining what a successful example would contain and what it would deliberately leave out. This makes the standard inspectable before anyone is assessed.

2 · Worked model

Separate four layers: input, astronomical result, named observance rule and authoritative local cross-check. Never hide one layer inside another.

I noticeI decideI verify
3 · Practise now

Put the source away and make a first attempt in ten minutes. Do not polish it. Reopen the source, underline corrections and write one sentence explaining why each correction mattered. Then use the result in a new situation.

Move the date or location across a boundary and compare results. Explain which change came from the sky and which came from the applied rule.

4 · Check the boundary

An astronomical instant is not automatically a festival or fasting decision. State the convention and confidence before giving practical guidance.

  • The result is visible: a reproducible input record.
  • A reader can distinguish source, interpretation, illustration and uncertainty.
  • The learner can explain the central move without looking, then correct it from the source.

Autosaved privately on this device.

Performance assessment

Evidence before completion

Four-part rubric
Accuracy
Claims match the cited source and limits are named.
Understanding
The learner explains relationships, not only wording.
Application
The central move works in a new case or audience.
Teaching
Another person can follow, question and verify it.
Inspect sources and classroom resourcesOpen
Starter library3 complete model resources

Open, use and adapt - not an empty shelf

These complete, source-linked resources accompany Vaiṣṇava calendar laboratory. Each one includes a bounded reading, a visual sequence, an immediate practice and a direct source trail. They may be reviewed, rewritten or replaced without misattributing authorship.

Study tools, folios and learning symbols
Read · see · attempt · verify · teach
Methods noteResearch edition

Astronomy first, observance rule second

A transparent calendar result separates sky calculation from a named religious convention.

Complete reading

The software can calculate lunar-solar elongation and rise or set times for a stated place and instant. A tithi is then an angular interval. Those results are reproducible astronomical inputs, not by themselves a complete decision about fasting, pāraṇa or a festival.

Practical observance requires a named rule-set and often sunrise conditions or other local criteria. Record the temple or authoritative calendar used for comparison and keep discrepancies visible for expert review.

Visual sequence
  1. 1Record inputs
  2. 2Calculate the sky
  3. 3Apply and cross-check rules
Do it now

Export one snapshot, change longitude by five degrees and explain which displayed values changed and why.

Source: Astronomy Engine · open calculation library
Boundary experimentResearch edition

See a tithi change instead of memorising a label

Three nearby snapshots turn a technical definition into an observable boundary.

Complete reading

Choose an instant close to a 12-degree multiple of lunar-solar elongation. Record snapshots before, near and after it. The tithi number should change when the interval changes, while the civil date may remain the same.

Repeat for a second longitude at the same UTC instant. Separate the astronomical state from the locally displayed clock. This prevents a date label from hiding the inputs that produced it.

Visual sequence
  1. 1Find a boundary
  2. 2Sample three instants
  3. 3Compare a second place
Do it now

Create a three-row table with time, location, elongation, interval and the practical question still requiring a rule-set.

Source: IMD · Rashtriya Panchang reference
Verification sheetResearch edition

How to cross-check a calendar result

A disagreement becomes useful when place, timezone, rule and edition are recorded.

Complete reading

Compare only results for the same location and civil-date convention. Copy the authoritative entry exactly, then list software input, computed result, applied rule and published result on separate lines.

Do not “fix” the software until the difference has been classified. It may arise from timezone, coordinates, sunrise model, tithi boundary, observance convention or a simple transcription error.

Visual sequence
  1. 1Align inputs
  2. 2Classify difference
  3. 3Escalate with evidence
Do it now

Write a discrepancy report that another reviewer can reproduce without contacting you.

Source: IES · worked examples and explanatory questions
Open practice and export toolsOpen
Complete local moduleAutosaves on this device

Learn by making something

Use the tool, inspect its limits, save evidence of your work, explain it to somebody else, then return and improve it. Model records are included so the workflow never begins as an empty form.

A study scene with learners, folios and a winding path
Encounter · recall · practise · discuss · teach · return
Astronomical inputs

Set time and place

Scope: this computes an astronomical snapshot. Ekādaśī observance, pāraṇa, festivals and Gaurābda dates require a named sampradāya rule-set and temple validation.

Transparent result

Śukla pakṣa, tithi 13

Lunar elongation

154.98°

Civil sunrise

Aug 26, 12:26 AM

Civil sunset

Aug 26, 1:19 PM

Brahma-muhūrta planning window

Aug 25, 10:50 PM – Aug 25, 11:38 PM

Moon phase and rise/set calculations use Astronomy Engine. The tithi number is derived from 12° lunar-solar intervals at the selected instant.

The learning rhythm

Every lesson moves from receiving to sharing

See the method
  1. 01Encounter
  2. 02Recall
  3. 03Apply
  4. 04Discuss
  5. 05Teach
  6. 06Return