The concept of lagna and the challenge of calculation of the same during day time are very well known. It is noteworthy that Mādhava devoted an entire book to address this problem of lagna determination. One of the interesting exercises involved here is to fix the coordinates of the point on ecliptic, which is on the horizon at any given instant. While a trained eye can easily fix it by actually looking at the horizon during the night, the day time poses a challenge. This is dependent on the time of the year, the time of the day and the latitude of the observer. The procedure requires the calculation of the quantity called cara, which is the excess or deficit duration of half day over the mean value of six hours. This is applicable to all celestial bodies and not only the sun. In short this is the duration by which the sun (or the celestial body) rises later or earlier than the mean value of 6’o clock; here it is assumed that the noon transit occurs exactly at 12:00 noon (or the time of noon transit of the celestial body).

中文翻译：

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通讯：关于卡拉的替代解释

lagna的概念以及在白天进行计算的挑战是众所周知的。值得注意的是，马哈达瓦（Mādhava）专门花了整本书来解决这种千真万确的问题。这里涉及的有趣的练习之一是将点的坐标固定在黄道上，黄道在任何给定的时刻都在地平线上。尽管训练有素的眼睛可以通过在夜间实际观察地平线来轻松地修复它，但白天却构成了挑战。这取决于一年中的时间，一天中的时间和观察者的纬度。该过程需要计算称为cara的数量，即超过六小时平均值的半天的过量或不足持续时间。这不仅适用于太阳，还适用于所有天体。简而言之，这是太阳（或天体）比6点钟的平均值晚或早升起的持续时间；这里假设中午凌晨恰好发生在中午12:00（或天体中午凌晨的时间）。