Timetable of 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. Low tide law

The fluctuation of sea water is regular. If we master the law of tidal fluctuation time, it will bring a lot of convenience to people's daily production and life. There is a way to calculate and master the time of daily tidal fluctuation. Take Qingdao as an example. The sea area near Qingdao is a regular semidiurnal tide. According to the normal semidiurnal tide, the period of each tidal activity is 12.4 hours, which fluctuates twice a day. In other words, the daily ebb and flow time is about 0.8 hours later than the previous day. Some people sum up the daily climax time as the following two formulas:

From the first day to the fifteenth day of each month, (lunar date-1)×0.8+5 (points); Every month 16 to the end of the month is (lunar date-16)×0.8+5 (points). These two formulas can calculate when the day is the highest tide, the lowest tide time is 6.2 hours later, and the high tide time is 6.2 hours later.

The specific fluctuation time of tides varies from place to place. Mainly depends on the date of the lunar calendar, local tidal types and longitude. If we carefully observe the local tidal law and refer to the above formula, we can calculate the local formula for calculating tidal time.