Reading a muhurta table without panic

An Indian almanac sheet has a grid on it. Fifteen numbered rows for the daytime, fifteen for the night, each row with a start time and an end time. Above the grid there is a small header: a city name, and the day's sunrise and sunset.

The header is doing all the work. The rows are just the daylight chopped into 15 equal pieces, and then the night chopped into 15 equal pieces.

That explains something odd. Each row is called a muhurta, and people will tell you a muhurta is 48 minutes. Forty-eight is what you get if you cut a full 24 hours into 30. But this page is not cutting 24 hours. On one Delhi sheet the sun was up for thirteen and a half hours, so each daytime row came to 54 minutes, while each night row came to 42. Nothing is wrong. The rows follow the sun, and the sun does not keep the same hours all year.

Most of the rest of the page works the same way. Rahu kaal, and the two windows printed beside it, are each one eighth of the daylight, picked by the day of the week. Durmuhurta simply points at one or two of the 15 rows.

A few entries are built differently. Varjyam and amrita kalam are not slices of the daylight. They hang off the nakshatra, the patch of sky the moon is currently crossing, and where they fall is looked up in an old table of 27 values, one per patch.

So there are three kinds of entry. Some are measured from where the sun and moon actually are. Some are shares of the daylight, worked out by division. Some are looked up in inherited tables. Knowing which kind you are reading tells you what it means when two sheets disagree.

Three things are worth checking. Whose city and whose sunrise the sheet used. Which of the three kinds the entry is. And what the window is actually for, since almost all of them are about starting something, and none of them is a forecast.