But the Chinese year has always been luni-solar. From the earliest times they had observed the twelve ecliptical "mansions" and zodiacal signs, and also that the time occupied by the sun in travelling through a mansion was rather longer than one lunation, or the time intervening between two new moons. Their object has accordingly always been to bring the lunar and solar years into manageable combination, so that the equinoxes, solstices, and "seasons" might occur with as much regularity as possible in the same months, and so that the husbandman might know when to sow his grain. Formerly they regulated this discrepancy according to the mean movements of the sun and moon; but, ever since the Jesuits first instructed them more accurately, they have regulated the two years, that is, the solar year and the twelve lunations, according to the true movements, and with reference to the meridian of Peking. If the moons were each exactly 29 1/2 days in length, instead of being 44 minutes 2.87 seconds longer, it would have been a simple matter to halve the ordinary lunar year, and make six months "large" (30 days) and six "small" (29 days); but the extra 44 minutes and a fraction accumulate, and the result is that there must always be a larger number of "great" months than "small" in the year. The way the Chinese arranged this was to call a month "great" (30 days) if the interval between mid-night (beginning of the new-moon day) and the hour of the _next_ new moon was full 30 days or over in duration; if less than 30 days, then the month was a "small" one (29 days). Not more than two long months ever followed in succession, and two short months never did so.