Ruling · Buddha Pūrṇimā (Vaiśākhī Pūrṇimā) · 2027

Wednesday 19 May

Determinatein Chicago, under the Rashtriya Panchang method. Clear of every threshold by 384 minutes.

Decide it for

ChicagoDelhiKolkataSingaporeSydneyJersey City

41°51′ N 87°39′ W · America/Chicago · GeoNames 4887398

The two middays

One ghaṭī is 24 minutes. Madhyāhna is 1 ghaṭikā either side of midday.

Midday of Wednesday 19 May

Taken. The only midday Pūrṇimā reaches.

madhyāhna begins 12:23  13:11 madhyāhna ends
11:3511:5912:2312:4713:1113:3513:59

48 of 48 minutes covered

Midday of Thursday 20 May

Pūrṇimā is absent from madhyāhna. Not taken.

madhyāhna begins 12:23  13:11 madhyāhna ends
11:3511:5912:2312:4713:1113:3513:59

0 of 48 minutes covered

Pūrṇimā presentMadhyāhna, the window the rule readsThe instant the tithi begins or ends

How it was decided

  1. 01

    Aṅga

    Pūrṇimā runs from 05:33 on Wed 19 May to 05:59 on Thu 20 May.

    2027-05-19T10:33:22Z → 2027-05-20T10:59:02Z

  2. 02

    Kāla

    Madhyāhna is 1 ghaṭikā either side of midday: 12:23–13:11 on the 19th, 12:23–13:11 on the 20th.

    madhyahna: midday-pm-1-ghatika · sunrise and sunset: upper limb, 31′ + 16′

  3. 03

    Rule

    Pūrṇimā must be present during madhyāhna. It covers 48 of 48 minutes on the 19th and 0 of 48 on the 20th.

    Calendar Reform Committee 1955, General Rules for Religious Festivals, p. 102

  4. 04

    Tie-break

    Only one midday qualifies. No tie-break is needed.

    priority: unstated → only-day · margin 23064 s

  5. 05

    Ruling

    Buddha Pūrṇimā, Chicago, 2027: Wednesday 19 May.

    confidence: determinate

Say it like this

In Chicago, Buddha Pūrṇimā (Vesak) 2027 falls on Wednesday 19 May. Pūrṇimā runs from 05:33 on Wed 19 May to 05:59 on Thu 20 May and covers all of madhyāhna that midday.

ahargana.org/chicago/festivals/2027/buddha-purnima · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingWed 19 May
Ahargaṇa, classicalDisc centre, no refractionWed 19 May
compat-drikpanchangComparison profileWed 19 May
No institution has a recorded ruling for Chicago.

Institutional rulings are recorded with a source address, and are never edited to agree.

The rule, as data

/rules/buddha-purnima · ruleset 2026.3-draft

Month
Vaiśākha, amānta
Pakṣa · aṅga
Śukla · Pūrṇimā
Kāla
Madhyāhna
Priority
Unstated
Tie-break
Longer coverage, as a boundary
Reference
CRC 1955, p. 102

“S 15 Sampat gauri vrata (paraviddha), Phuladola (Bengal & Orissa) (paraviddha), Gandhesvari puja (Bengal) (purvaviddha), Buddha purnima, Vaisakhi purnima.” Calendar Reform Committee 1955, General Rules for Religious Festivals, p. 102.

The same rule, elsewhere

Twelve places, west to east. Local clock times.

PlacePūrṇimāMadhyāhna 19thCoveredMadhyāhna 20thCoveredRuled
Los Angeles03:33 → 03:5912:2648 min12:260 min19 May
Chicago05:33 → 05:5912:2348 min12:230 min19 May
Jersey City06:33 → 06:5912:2948 min12:290 min19 May
Port of Spain06:33 → 06:5911:3948 min11:390 min19 May
London11:33 → 11:5912:3348 min12:330 min19 May
Durban12:33 → 12:5911:280 min11:2848 min20 May
Dubai14:33 → 14:5911:510 min11:5148 min20 May
Delhi16:03 → 16:2911:540 min11:5448 min20 May
Kolkata16:03 → 16:2911:090 min11:0948 min20 May
Singapore18:33 → 18:5912:370 min12:3748 min20 May
Sydney20:33 → 20:5911:270 min11:2848 min20 May
Suva22:33 → 22:5911:390 min11:3948 min20 May
Profile · tradition
pac-rp@2026.1 · smarta
Rule
buddha-purnima@2026.3-draft
Engine · kernel
0.1.0 · de440 7eef…ea74
Boundary margin
300 s