What is the timetable for high tide and low tide?

Because the high tide and low tide of seawater are geographical phenomena influenced by the gravity of the moon, they can follow regularly, with a period of 15 days. Therefore, the next day's high tide is 0.8 hours (48 minutes) later than the previous day, and the daily high tide time can be calculated according to the lunar calendar date. The specific calculation method is as follows: according to the lunar calendar, if the number of days is less than 15, if the number of days is greater than 15.

You must subtract the number of days from 15 and multiply it by 0.8 to get the highest climax time of the day. At the same time, the interval between high tide and low tide is generally 6 hours, which means that high tide and low tide are twice a day. The high tide generally lasts for more than an hour before the low tide begins, and the low tide time is at least between the two high tides.

Extended data

Although the tidal force of the sun is not too great, it can affect the size of the tide. Sometimes they work together with the moon to complement each other, and sometimes they repel and cancel each other out. At the new moon or full moon, the sun and the moon exert gravity in the same direction or in the opposite direction, resulting in climax; But in the first quarter or the second quarter, the gravity of the moon is opposite to that of the sun, leading to low tide. Its cycle is about half a month. From a year's perspective, there are also two high tides and two low tides.

At the vernal equinox and autumnal equinox, if the earth, the moon and the sun are almost on the same plane, the tidal force is greater than that in other months, resulting in two climaxes in spring and autumn. In addition, tides are also related to the distance between the moon and the sun from the earth. The moon's orbit is elliptical, approaching and leaving the earth once every 27.55 days. Near-earth tides are 39% larger than far-earth tides. When the near-earth tide coincides with the high tide, the tidal range is particularly large. If the distant tide and low tide coincide, the tidal range is particularly small.