Hindus worldwide celebrate Krishna Janmastami which comes in the month of Shravana, on the eight day (ashtami) of the Krishna Paksha. The birth of Rama is celebrated on the ninth day (navami) of Shukla Paksha of Chaitra month - as Rama Navami.
Mapping Hindu festivals to the Tithi dates also helps us track our birthdays by referring to any Calendars in our homes. Suppose you were born on the day of VijayaDashami, then every year your birthday would coincide with the festival. Same is true about Krishna Ashtami, Rama Navami and Ganesh Chaturthi. These festival dates can be referred in many online websites or local calendars.
Not just birthdays but also anniversaries are celebrated by hindu calendar. Shri Rama and Devi Sita’s wedding anniversary is celebrated as Vivah Panchami. Which comes on the fifth (panchami) day of Shukla Paksha of the month Margashirsha.
Similar Vivaah Tithi calculation can be done to celebrate wedding anniversaries as per the hindu calendar.
For the uninitiated, here is a quick brief on the hindu calendar structure.
Tithi: A lunar calendar is based on the moon's rotation around the Earth. A tithi corresponds to a phase of the moon and is calculated as the time taken for the longitudinal angle between the moon and the sun to increase by 12°. A full day is measured from Sunrise to Sunrise, while the start time and duration of a tithi keeps varying. A day is named after a Tithi i.e. Ashtami or Navami if the Sunrise timing of that day falls within the Tithi period. It is possible that the two Tithis fall within the duration of a single day (Tithi kshaya) or a single Tithi duration may be spread across two days (adhika tithi).
1.Pratipada 2.Dwitiya 3.Tritiya 4.Chaturthi 5.Panchami 6.Shashthi
7.Saptami 8.Ashtami 9.Navami 10.Dashami 11.Ekadashi 12.Dwadashi
13.Trayodashi 14.Chaturdashi 15.Poornima / Amavasya
Paksha: The lunar months are split into two Pakshas of 15 tithis each. The waxing of the moon is called Shukla Paksha (Shukla means white in Sanskrit), Amavasya to Purnima. The waning of the moon is called the Krishna Paksha (Krishna means dark), Purnima to Amavasya.
There are two different systems for making the lunar calendar: Amavasyantha or mukhya-mana system where a month cycle is from a new moon to a new moon, mostly followed in the South Indian states and Purniamantha or gauna-mana system where a month cycle is from a full moon to a full moon, followed mostly in the North Indian states.i
There are 12 months in a Hindu Year. Each month consists of 2 pakshas, each containing 15 tithis each which amounts to 30 tithis per month. Determining, which name a lunar month takes is somewhat indirect. It is based on the Rashi (Zodiac sign) into which the sun transits within a lunar month, i.e. before the new moon ending the month. When the sun does not at all transit into any Rashi but simply keeps moving within a Rashi in a lunar month (i.e. before a new moon), then that lunar month will be named according to the first upcoming transit. It will also take the epithet of adhika or "extra" e.g Adhika Chaitra Masa. If the sun transits into two rashis within a lunar month, then the month will have to be labeled by both transits and will take the epithet kSaya or "loss". There is considered to be a "loss" because in this case, there is only one month labeled by both transits e.g. Pausa-Magha kSaya-masa. A kSaya-masa occurs very rarely.
1.Chaitra 2.Vaishakh 3.Jyeshtha 4 .Ashadh 5. Sharavan 6.Bhadrapadi
7.Asvina 8.Kartika 9. Margshirsh 10. Pausha 11. Magha 12.Phalgun
Nakshatra: The lunar ecliptic around the earth is divided into 27 Nakṣatra-s, which are variously called lunar houses or asterisms. These reflect the moon's cycle against the fixed stars, 27 days and 7¾ hours, the fractional part being compensated by the 28th nakṣatra, Abhijit. Birthdays are celebrated by nakshatra timings which is considered auspicious for birthday celebration pujas.
The Vedic Pujas department in Art of Living, Bangalore lists such pujas in their website:
Time in accordance with hindu calendar, as per hindu tradition has always been a critical part of spirituality and our culture. Janmatithi can be an auspicious time for us to take up charitable activities like tree plantations, feeding the poor, Donations ,Gaudhaan (Desi Cow dhaan) or in a your own special way.