Choghadiya today in London

Amrit (nectar) is the most favourable. Shubh (auspicious) and Labh (gain) are favourable, Labh especially for business. Char (moving) is neutral, and is usually considered fine for travel. Udveg (anxiety), Kaal (time, or death) and Rog (disease) are the three that tradition advises avoiding for new beginnings.

The daytime from sunrise to sunset is split into eight equal parts, and the night from sunset to the next sunrise into eight more. The first daytime period takes the name of the weekday: Udveg on Sunday, Amrit on Monday, Rog on Tuesday, Labh on Wednesday, Shubh on Thursday, Char on Friday and Kaal on Saturday. The names that follow go in a fixed order. The night uses a different fixed order, starting from a different name for each weekday.

Because the parts are fractions of the real day and night, each Choghadiya is about 90 minutes in a 12-hour day, but longer or shorter on other days, and the times differ from city to city.

Many people look for an Amrit, Shubh or Labh slot when they have a choice of time for something important, and avoid starting it in Udveg, Kaal or Rog. When the time is not up to you, the tradition does not ask you to postpone. Treat it as a convenience for choosing, not as a forecast.

London is far north, so its summer days are very long and its winter days short, which stretches and squeezes every Panchang period; it also changes its clocks in March and October.

Sunrise, sunset, moonrise and moonset come from the Navamsha astrology API; where it is not available they are computed by our own engine, which agrees with it to a fraction of a second. The moment each tithi, nakshatra, yoga and karana ends is computed by that engine from the positions of the Sun and Moon (NASA JPL DE421 ephemeris) in the sidereal zodiac with the Lahiri ayanamsa. Rahu Kaal, Choghadiya, Hora, Abhijit Muhurat and the other periods are fixed fractions of the day worked out from sunrise and sunset.

Almanacs differ in how they define sunrise. Here the Sun rises when the centre of its disc is on the horizon, with no allowance for refraction. Almanacs that use the Sun's upper edge and refraction show sunrise a few minutes earlier and sunset a few minutes later, and their Rahu Kaal and other periods move with it. For a ceremony, follow the Panchang your family priest or local temple uses.