How Often Do Lagna, D9 and D10 Change? Varga Durations

The usual answer is that the lagna changes every two hours. That is the average: twelve signs in one turn of the sky. At Delhi the real figure runs from 85 minutes for Pisces to 140 for Cancer, and almost every divisional chart cuts those spans finer. The navamsa (D9) lagna holds one sign for 9.3 to 15.7 minutes. The dashamsha (D10) holds for 8.4 to 28.2, a wider range than the D9 for a reason explained below. The shashtiamsha (D60) never holds longer than 2.4.

Every figure on this page was measured, not divided out. The site’s ascendant routine was stepped through one whole sidereal day at Delhi, every two seconds from midnight IST on 21 March 2026, and the sign of each divisional chart was recorded at every step under the Parashari rules. The figures are durations only. When a given sign rises depends on the date, and this page does not give the time of day for any of it.

The Rashi Lagna: Twelve Unequal Spans

Away from the equator the ecliptic meets the horizon at an angle that keeps changing through the day, so some signs come up steeply and quickly and others slowly and at a slant. Here are the twelve sidereal signs at Delhi, with Thiruvananthapuram in the far south and Jammu in the north for comparison:

The spread between the quickest and slowest sign is 27 minutes at Thiruvananthapuram, 55 at Delhi and 64 at Jammu. The farther north the birthplace, the less the two-hour rule describes it. For a lagna in Pisces or Aquarius, a given error in the birth time moves the ascendant farther than it would in Cancer. The ascendant calculator prints these spans for your own birthplace, along with how many minutes your lagna sits from the next sign.

All Sixteen Divisional Charts, Measured

A divisional chart cuts each sign into equal parts, except the D30, and gives each part a sign. Its lagna is the sign of the part the ascendant is in, so it changes whenever the ascendant crosses into a part that gives a different sign. “Runs” below counts those unbroken stretches over the whole day at Delhi:

For most charts the runs are just the parts, so a D-n chart has twelve times n runs, and the shortest run comes in the quickest sign and the longest in the slowest. Each chart’s own page, linked in the first column, sets out how its parts are counted. The shodashavarga overview lists the even-rate average for every part, four minutes a degree. The table here is what the uneven sky does to that average.

Why the D2, D10 and D24 Break the Pattern

Three charts have fewer runs than parts, because the last part of one sign and the first part of the next give the same sign. The divisional lagna then simply stays put across the boundary.

• D2 hora: the Parashari hora uses only Leo and Cancer, and every sign ends on the half that the next sign begins with. Twenty-four halves become 12 runs, each about as long as a whole rashi span (84.6 to 140.3 minutes) but set half a sign later. So the hora lagna changes twelve times a day, in mid-sign.
• D10 dashamsha: an even sign’s first part takes the sign its odd neighbour’s last part took, so 6 pairs join and the day has 114 runs instead of a hundred and twenty. The joined pairs are why the longest D10 run, 28.2 minutes, is far longer than any D9 run, even though the D10 has more parts.
• D24 chaturvimshamsha: odd signs start from Leo and even signs from Cancer, and 6 boundaries join the same way, which gives the D24 a longest run of 11.7 minutes, far longer than the D27 next to it in the list.

The D30 trimshamsha is the other exception, for a different reason. Its five parts per sign are five, five, eight, seven and five degrees wide, so its sixty runs vary more than any equal-part chart’s. Its longest, 37.5 minutes, outlasts the shortest run of the D3.

Latitude Moves Every Varga

A varga part is a fixed share of a sign, so whatever latitude does to the rashi spans, it does to every divisional chart in proportion. The navamsa lagna holds for 11.4 to 14.6 minutes at Thiruvananthapuram, 9.3 to 15.7 at Delhi and 8.8 to 16.0 at Jammu. For the D60 the same three ranges are 1.7–2.2, 1.4–2.4 and 1.3–2.4 minutes.

What This Means for a Recorded Birth Time

Suppose a birth time is good to five minutes either way, a 10-minute window. At Delhi that window is longer than the shortest navamsa run and shorter than the longest. In Pisces, where every navamsa lasts under 10 minutes (at most 9.7), the window always contains at least one D9 change. In Cancer, where every navamsa lasts more than 10 (at least 15.5), it contains at most one. The same window always holds at least four D60 changes. That is why the finer charts are only as good as the time they are built from, and why a chart built on an approximate time is best read from the rashi chart and the slower vargas. What a chart can and cannot give without any time at all is set out in kundli without birth time.

The grahas’ own varga positions are much steadier, because they move far more slowly than the ascendant. The Moon is the fastest of them. Through 2026 it covers 11.8° to 15.3° a day, so its navamsa, which is its nakshatra pada, lasts 5.2 to 6.8 hours, and its nakshatra 20.9 to 27.1 hours. For the Moon’s varga positions, the birth time matters far less than for the lagna’s, except when the Moon sits right at the edge of a part. The difference between the Moon sign and the lagna is laid out in rashi and lagna.

In Brief

• Rashi lagna at Delhi: 85 to 140 minutes per sign, not a flat two hours
• D9 navamsa: 9.3 to 15.7 minutes, 108 changes a day
• D10 dashamsha: 8.4 to 28.2 minutes, 114 runs because some parts join
• D60 shashtiamsha: 1.4 to 2.4 minutes, 720 changes a day
• Farther north: a wider gap between shortest and longest, in the rashi chart and in every varga