This calendar calculates Vaishnava events and Panjika/Panchang (Hindu calendar) for chosen location.
Now it calculates 100 Gaurabdas (or 100 years) and displays Purnimanta masas in Gregorian month views.
It has the module for Exporting events to Google Calendar, giving you the opportunity to use your favorite Widget or Calendar. It also exports events to Local Calendar and to the Clipboard (for further saving the list of events to a CSV file and importing it into MS Exchange, Yahoo and other applications).
It is based on Shri Navadwipa Panjika and contains main Vaishnava and ISKCON events.

Features:
• The number of supported Vaishnava events is 157
• It is offline application - it does not require Internet connection.
• It doesn't retrieve or store any identifying information.
• It has simple interface.

Current functionality:

1) Month view shows:
- current day
- Ekadashi fasting and Parana (time of breaking the fast)
- Purnima (full moon) and Amavasya (new moon)
- Vaishnava holidays
- as well as my own events

2) Day view shows:
- Hindu calendar - Panchang/Panjika: tithi(with end time), paksha, nakshatra, yoga, karana and vaara
- Gaurabda, Chandra varsha and year
- Gaudia Vaishnava masa and Purnimanta masa (months)
- Brahma Muhurta
- sunrise and sunset
- noon
- moonrise and moonset
- for Ekadashi vrata days additionally:
-- the time when fasting begins
-- the period of breaking the fast
-- description of Ekadashi
- for Vaishnava holidays additionally:
-- description
-- info about fasting

3) Daylight Saving Time (Summer Time) support for Europe, USA and Australia

4) built-in database of 4,000 cities to select 'Current location'

5) follows the rules given by Srila Bhaktisiddhanta Saraswati Thakura in His "Shri Navadwipa Panjika" to cultivate Sri Harinam Kirtan worldwide. "Sri Navadvip Panjika" was designed according to Vaisnava Smriti - "Śrī Hari-bhakti-vilāsa" (by Sanātana Gosvāmī").

6) supports only Vaishnava (or Bhagavata) Ekadashi which are Shuddha (pure): an observance is based on the rule that Dasami (the tenth day) during a lunar fortnight should have ended before Arunodaya (96 minutes period before sunrise on the Ekadasi or the 11th day in a lunar fortnight). Note that Smartha Ekadashis are not supported (but available in any Hindi calendar).

7) full support for ISKCON:
Both algorithms of calculating the start of the fasting have been implemented:
-- a) using Mayapur city (near Navadvipa, West Bengal, India)
-- b) using the 'Current location'
Notes for ISKCON:
-- a) used by AC Bhaktivedanta Swami Srila Prabhupada. This algorithm was widely used until 1990
-- b) alternative algorithm proposed in 1990

8) supports Hindi, Bengali, English, Ukrainian, Russian, Hungarian, Portuguese, Spanish, Italian, French

9) has feature "Export events" to:
-- Google calendar (with cloud synchronization)
-- Local/Offline calendar (without cloud synchronization)
-- Clipboard (for saving in CSV file and using in MS Outlook, Yahoo or Google further)
How to work: https://youtu.be/w3JUKdV0OEU
This feature has configuration options similar to "Notify events", and additionally allows to set "Time interval" to:
-- current month
-- current masa (lunar month)
-- from now till Gaura Purnima
-- all Gaurabda (lunar year)

10) "Set Date" is a part of time machine which can be used to travel to an arbitrary point in time (currently years 1961-2061 are supported) and get information for that moment.
Note: the application doesn't save a time or info between sessions. Every time the app is launched it takes current time from system clock and makes calculations again.