Three years ago I shared an ICS feed so Gurpurabs would show up in our phone calendars without a separate app. It worked, people subscribed, and I kept patching it. But the more I checked its dates against the official Jantri — the printed calendar published from Amritsar every year — the less they agreed. This year I stopped patching and rebuilt the whole thing from scratch. If you already subscribe at janpreet.com/nanakshahi, you don’t need to do anything — the same URL now serves the rebuilt feed.

Why the old one couldn’t be fixed

My original feed stood on the 2003 Nanakshahi calendar: a tidy arithmetic design where every month starts on the same Gregorian date each year. The problem is that the Jantri as actually printed hasn’t followed that design for over a decade — it reverted to the Bikrami system under Nanakshahi labels. Concretely:

  • Month starts are sankrantis — real astronomical moments, so month lengths change every year. Jeth had 32 days in NS 557; in NS 558 it’s Sawan that gets 32. A fixed table can’t represent that.
  • Every Guru parkash, gurgaddi and joti-jot day moves on a Bikrami tithi. Parkash Guru Nanak Dev Ji is Katak purnmashi — 5 Nov 2025, then 24 Nov 2026. Shaheedi Guru Arjan Dev Ji is Jeth sudi 4. None of these sit still in either the Nanakshahi or the Gregorian calendar.

So any feed built on fixed dates — mine included — drifts wrong within a year or two. For a calendar people actually plan around, that’s not a bug to patch; it’s the wrong foundation.

What the rebuild does

1. The printed Jantri is the ground truth. I extracted three published years — NS 549 (2017-18), 557 (2025-26) and 558 (2026-27) — page by page, digit by digit. The PDFs have no text layer, and Gurmukhi numerals have cruel look-alikes (੨/੭, ੫/੬/੯, ੮/੯ — an earlier misread of exactly this kind is how my old data went bad), so every date was verified at high zoom against the day-grid numbers, which are arithmetically forced. Each date in the feed carries its source, down to the page.

2. An astronomical engine fills in every other year. Under the pinned data sits a proper drik computation — sidereal sun for sangrands, sunrise tithis at Amritsar for the lunar dates, adhik months, kshaya/vridhi tithis, even the pradosh and aparahna rules for Bandi Chhor Divas and Dussehra. Calibrated against every single extracted data point, it reproduces 36/36 sangrands and 132/132 tithi dates across the three pinned years. That means the feed already contains NS 559, 560 and beyond — no waiting for anyone to type next year in.

3. Honesty about which is which. Dates confirmed by a published Jantri appear normally; dates computed for years with no Jantri yet are prefixed with ≈ and say so in their description. When the new Jantri comes out each spring, pinning it takes about fifteen minutes, and that year’s ≈ marks disappear. A few observances that the Jantri itself moves around unpredictably are never guessed at all — they only appear once printed.

What you get

  • The feed (same URL as always): janpreet.com/nanakshahi — Gurpurabs, itihasik dihade, bhagat sahiban de dihade, sangrands, massia/purnmashi, and daily Nanakshahi dates, in Punjabi and English. Rebuilt from source by CI on every change and monthly on a schedule.
  • A web calendar: janpreet.github.io/nanakshahi-ical — browse any year month by month, with confirmed/estimated badges on every event.
  • A reusable engine: the calendar logic now lives in its own package, nanakshahi-jantri (npm install nanakshahi-jantri), so you can build your own things on it — widgets, bots, gurdwara displays. The ICS project is now just a thin consumer of it.

Subscribing (if you haven’t already)

Google Calendar: Other calendars → From URL → paste janpreet.com/nanakshahi.

Apple Calendar / iPhone: Settings → Apps → Calendar → Calendar Accounts → Add Account → Other → Add Subscribed Calendar → paste the same URL.

My earlier posts credited the nanakshahi-js library, which faithfully implements the original 2003 calendar — it served this project well, and the parting is purely because the printed Jantri went a different way. This rebuild follows the Jantri, wherever it goes: when the math can predict it, it does; when only Amritsar can say, the feed says so too.

ਵਾਹਿਗੁਰੂ ਜੀ ਕਾ ਖ਼ਾਲਸਾ, ਵਾਹਿਗੁਰੂ ਜੀ ਕੀ ਫ਼ਤਿਹ। Feedback and corrections welcome — especially if you have older printed Jantris lying around; every extra year makes the engine’s calibration stronger.