Digital and printed panchangs
Digital and printed panchangs can differ, because they use different ayanamsas, sunrise conventions, models and rules for end times. Both are used in practice.
What it is
A digital panchang is convenient and updates for any date, while a printed one is fixed and often follows a regional tradition. For a date that matters, check both and note the difference.
How it is worked out or read
When two panchangs differ, check the ayanamsa, the city, and the sunrise convention first. The remaining differences are usually small.
Where it appears on this site
See who makes a panchang and comparing software.
What a printed panchang offers
A printed panchang is prepared once a year for a particular place or region, usually a major city, and its tables give the tithi, nakshatra, yoga, karana, sunrise, sunset and festival dates for every day of the year. Many households keep the same publisher's panchang for generations, and its conventions, regional festivals and month names become part of family practice. A printed almanac also carries the editor's judgement on difficult cases, such as which day a festival should be kept when a tithi spans two sunrises.
Its limit is that it is fixed to one location. Sunrise in a city several hundred kilometres away can differ by many minutes, and every sunrise-based timing in the almanac shifts with it.
What a digital panchang offers
A digital panchang computes the same quantities on demand for any date and any place. If a reader enters their own city, the sunrise, Rahu Kaal, choghadiya and tithi end times are calculated for that city rather than borrowed from a regional reference. This is especially useful for people living far from the place a printed almanac was made for, including those outside India. A digital tool can also show any date in the past or future, which helps in checking birth details or planning ahead.
Its limit is that the user may not know which conventions the software follows: which ayanamsa, which sunrise definition, which rule for festivals. Without that information it is hard to explain a disagreement with a printed almanac.
Why they sometimes disagree
Most disagreements between the two have ordinary causes. The location may differ. The sunrise may be defined by the Sun's upper edge in one and its centre in another, and refraction may be included or not. The ayanamsa may differ slightly, which moves nakshatra end times. A festival rule may differ between traditions. And older printed almanacs may still use siddhanta-based calculations rather than modern astronomy, which can shift times by minutes or more.
When a difference appears, the reader should check these causes one by one before concluding that either source is wrong.
Using both well
Many readers use both: the family's printed panchang for festivals and customs, and a digital tool for exact local times. This site's panchang states its conventions on the page, including the ayanamsa and the fact that values are taken at sunrise, so a reader can compare it with a printed almanac knowing what each assumes. For family observances, the community's printed almanac often remains the reference people agree on, and that shared agreement has its own value.