How to calculate the time of high and low tide?

The calculation formula is as follows:

The first to fifteenth day of the lunar calendar: high tide time = date *0.8.

16th to 30th day of the lunar calendar: high tide time = (date-15)* 0.8.

The law of high tide and low tide is that there are two high tides every day, and the interval is 12 hours. The high tide usually lasts for more than an hour before it begins to ebb, and the lowest time of ebb is in the middle of the two high tides.

The time of high tide is different every day, and it comes back every 15 days. Therefore, the climax of the next day is 0.8 hours (48 minutes) later than that of the previous day, and the daily climax time can be calculated according to the lunar calendar date.

High tide is a natural phenomenon. There are high tides and low tides in seawater. At high tide, the sea rises, the waves roll and the scenery is spectacular. At low tide, the sea receded quietly, revealing a beach. High tide and low tide are usually twice a day.

Extended data:

Because the fluctuation of seawater is a geographical phenomenon influenced by the gravity of the moon, the fluctuation of seawater is regular, and its period is 15 days.

The regular semidiurnal tide fluctuates once every 12 hour. The simple calculation method of tidal time is: maximum tidal time = lunar calendar ×0.8, minimum tidal time = maximum tidal time +/-6.

Suppose: today is 15 of the lunar calendar, and the highest climax time is = 15×0.8= 12, that is,12 at noon and midnight; The lowest ebb time is 6 am and 6 pm. Close observation time is from 4 am to 8 am and from 4 pm to 8 pm.

Therefore, the climax of the next day is delayed by 0.8 hours (48 minutes) on the first day, and the daily climax 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, directly multiply the number by 0.8 to get the highest tidal time of the day; If the number of days is greater than 15.

You must subtract the number of days from 15, and then multiply it by 0.8 to get the highest climax time in a 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 usually lasts for more than an hour before it begins to ebb, and the lowest time of ebb is in the middle of the two high tides.

Generally speaking, the tidal range between two tides in a day is not equal, and it is not equal at high tide and low tide. This irregular phenomenon is called the daily inequality of tides. The high tide is called high tide, and the low tide is called low tide; Low tide is called low tide and high tide is called high tide.

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