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Table of Contents
2. Extract some information from date and time: DATE() , MONTH() , YEAR() , HOUR() , etc.
3. Calculate the time difference: DATEDIFF() , TIMEDIFF() , TIMESTAMPDIFF()
4. Format output: DATE_FORMAT()
Home Database Mysql Tutorial Working with Date and Time Functions in MySQL Queries

Working with Date and Time Functions in MySQL Queries

Jul 07, 2025 am 01:10 AM
mysql date time

The date and time functions in MySQL queries can be efficiently processed through 4 common methods. 1. Get the current time: NOW() returns the full time, CURDATE() returns only the date, CURTIME() returns only the time, it is recommended to select and pay attention to time zone issues as needed; 2. Extract some information: Use functions such as DATE(), MONTH(), YEAR(), HOUR() to be used for WHERE and GROUP BY operations, but may affect the index performance; 3. Calculate the time difference: DATEDIFF() calculates the date difference, TIMEDIFF() calculates the short time difference, TIMESTAMPDIFF() supports flexible units, and is recommended for complex calculations; 4. Format output: DATE_FORMAT() can format the date as needed, suitable for report display. Mastering these functions can cover most of the time-processing scenarios.

Working with Date and Time Functions in MySQL Queries

It is actually very common to process date and time functions in MySQL queries, especially when making reports, filtering time period data, or calculating time difference. The key is to understand the usage of several commonly used functions and the differences between them.

Working with Date and Time Functions in MySQL Queries

1. Get the current time: NOW() vs CURDATE() vs CURTIME()

These three functions return different time information:

Working with Date and Time Functions in MySQL Queries
  • NOW() returns the full current date and time, such as '2025-04-05 14:30:00'
  • CURDATE() only returns the date part, such as '2025-04-05'
  • CURTIME() only returns the time part, such as '14:30:00'

suggestion:

  • If you only need dates, don't use NOW() to avoid partial interference from unnecessary time.
  • Note the time zone problem: These functions return the time under the server's time zone set. If your application involves multiple time zones, it is best to use UTC time uniformly and convert it.

2. Extract some information from date and time: DATE() , MONTH() , YEAR() , HOUR() , etc.

Sometimes we want to group statistics based on year, month or hour, and we can use these extract functions.

Working with Date and Time Functions in MySQL Queries

For example:

 SELECT YEAR(order_date) AS order_year, COUNT(*) AS total_orders
FROM orders
GROUP BY order_year;

Commonly used extraction functions include:

  • DATE(order_date) extracts the date part
  • MONTH(order_date) extracts months (1~12)
  • DAYOFWEEK(order_date) returns the day of the week (1=Sunday, 7=Saturday)
  • HOUR(login_time) extraction hours

hint:

  • These functions are useful in both WHERE and GROUP BY .
  • However, pay attention to the use of indexes - if the fields are processed, the index may not be used, which affects performance.

3. Calculate the time difference: DATEDIFF() , TIMEDIFF() , TIMESTAMPDIFF()

All three are used to compare the differences between the two time points, but their uses are slightly different:

  • DATEDIFF(date1, date2) returns the number of days where two dates differ (ignoring the time part)
  • TIMEDIFF(time1, time2) returns the time difference between two times (no more than 24 hours)
  • TIMESTAMPDIFF(unit, datetime1, datetime2) is more flexible and can specify units (such as minutes, hours, days, etc.)

For example:

 SELECT DATEDIFF('2025-04-06', '2025-04-05'); -- Return 1
SELECT TIMESTAMPDIFF(MINUTE, '2025-04-05 14:00', '2025-04-05 15:30'); -- Return 90

Notice:

  • DATEDIFF is a comparison of "date only", and even if there is a specific time, it only depends on the date.
  • TIMEDIFF is only suitable for situations where the time span is small.
  • TIMESTAMPDIFF is the most general and is recommended for complex time difference calculations.

4. Format output: DATE_FORMAT()

When you want to display dates in a specific format, you can use DATE_FORMAT() function.

Example:

 SELECT DATE_FORMAT(order_date, '%Y-%m-%d') AS formatted_date FROM orders;

There are many supported format characters, commonly used ones:

  • %Y four digit year
  • %y two digit year
  • %M full month name (January)
  • %b abbreviation month name (Jan)
  • %d two digit date
  • %H 24-hour hours
  • %i minutes
  • %S seconds

This function is very useful when generating reports or presenting them to users.


Basically that's it. Although there are not many date and time functions in MySQL, they can solve most scenarios by combining them. The key is to remember the characteristics and scope of application of each function to avoid misuse.

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