Time function, try to popularize it before learning. Microsoft uses the 1900 commemoration method (the number 1 represents January 1, 1900, and the number 1.5 represents 12:00 noon on January 1, 1900, Because 1.5 is exactly 1 and a half days, and 24 hours a day, half a day is 12 hours) Therefore, it can be converted into hours according to a decimal, the formula: 1 day = 24 hours to calculate a decimal to convert into hours and multiply by 24 However, if you multiply it by another 60, it will be converted into minutes, and if you multiply it by another 60, it will be converted into seconds. It is very simple: 1 day = 24 hours = 1400 minutes = 86400 seconds
date (date function) It takes 3 parameters, which are year, month, and day.
Function syntax: The three parentheses in the middle of date (year(), month(), day()) are the referenced cell positions
datedif (calculation time interval function) is the number of years, months, and days from which date to which date.
Function syntax: datedif (start date, end date, what unit is used) The third parameter is "y" when the year is expressed, "m" when the month is expressed, and "d" when the day is expressed
In addition, "ym" represents the number of months left in the whole year, and "md" represents the number of days left in the whole month. These two third parameters are the remainder, and the quotient is not displayed.
weeknum (calculating a date is the week number function of the year)
Function syntax: weeknum (which date, the start date of the week is calculated according to the day of the week) because the United States and other countries regard Sunday as the first day of the week, the second parameter has a drop-down remark option, 1 is Sunday, 2 is Monday
weekday (calculate the day of the week a date is this year)
Function syntax: weekday (which date, in what form) because the United States and other countries regard Sunday as the first day of the week, the second parameter has a drop-down remark option, 1 is Sunday, 2 is Monday
text (to completely transform a date (number) into another) is like changing a date to a custom conditional format before, entering aaaa will get a day of the week, but copying this cell and pasting it elsewhere will turn it into a number, use This function can paste the changed day of the week style directly to the location without turning it into a number
Function syntax: text (who to transform, "") "" should add a custom syntax format, such as =text(B3, "aaaa")