This article applies to either a Microsoft Access database (.mdb) file or to a Microsoft Access database (.accdb) file, and to a Microsoft Access project (.adp) file.
Moderate: Requires basic macro,
coding, and interoperability skills.
This article describes the functions and the operators that are
available in Microsoft Office Access 2007, in Microsoft Office Access 2003, and in Microsoft Access 2002. You can use the functions and the operators to make a change to the Date/Time
data type by using example queries. The example queries that you can use to make a change to
the date values use the tables in the Northwind.mdb sample database.Note
The Northwind sample database for Access 2007 does not use the same fields as the earlier versions of the Northwind sample database. There are no HireDate and BirthDate fields in the Employees table that is included with the Northwind sample database for Access 2007. The EmployeeID field has been renamed ID and the FirstName field has been renamed First Name.
Access provides operators and
functions to validate or to make a change to the fields with the Date/Time
data type. The following example queries use the date
manipulations, the calculation functions, and the comparison operators that are
available in Access.
Microsoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure. However, they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements.
Date() function, Now() function, and Format() functionThe Date() function returns the current date in the short-date
format. The Now() function returns the current date with the time.
You can use the Format() function with date values to specify the
date format that you want to use for the date. This example query returns the current
date in the long date format (01 December 2003).
SELECT Format(Now(), "dd mmmm yyyy");
Day() function, WeekDay() function, Month() function, and Year() function
From the Employees table, this query returns the date of hire, the day of hire, the day of the week of hire, the month of hire, and the year of hire for each employee. Notice that
the WeekDay() function returns a numeric value that indicates the day of
SELECT HireDate, Day(HireDate) AS Day,
Weekday(HireDate) AS WeekDay,
Month(HireDate) AS Month, Year(HireDate) AS Year
From the Employees table, this query returns all the employees who
were born before the year 1960. The DatePart() function can be used to extract the
part of the specified date, such as the day, the month, or the year.
SELECT * FROM Employees
WHERE DatePart("yyyy", BirthDate) < 1960;
From the Employees table, this query returns the employee ID, the first name, the date of birth, and
the age of each employee. The DateDiff() function
returns the difference or the time lag between the two specified date values (in terms of
the day, the month, the year, or the time units, such as hours, minutes, and seconds).
SELECT EmployeeID, FirstName, BirthDate,
DateDiff("yyyy", BirthDate, Date()) AS Age
From the Employees table, this query returns the employee ID, the first name, the hire date, and the
date that the employee finishes 10 years of service with the
company. The DateAdd() function
increments a date by a specified number of time units, such as a day, a month, or a year
and then returns the resultant value.
SELECT EmployeeID, FirstName, HireDate,
DateAdd("yyyy", 10, HireDate)
You can add a numeric value
to a date value directly. Do this to increment the date value by a day, as in the
following example:This query increments the current date by one day and then returns the
resultant date value.
The DateValue() function verifies whether the input string is a valid
date. If the input string is recognized as a valid date, the
date is returned in short-date format. If the input string is not recognized as a valid date, the statement "Data type mismatch in criteria expression" is returned. The DateValue() function recognizes a variety of date
formats, such as mm dd yyyy, dd mm yyyy, dd mmm yyyy, and
dd mmm yyyy hh:mm:ss long date format.
SELECT DateValue("20 Nov 2003") AS ValidDate;
The DateSerial() function returns the date value for the specified
input parameters of year, month, and day. The input parameters can be
expressions that involve arithmetical operations. The DateSerial() function
evaluates the expressions in the input parameters before it returns the
resultant date value.
SELECT DateSerial( 2003, 03, 1-1);
This example query returns the last day in the
month of February for the year 2003. The last input parameter for the day with
the value of 1 is decremented by 1. The result is that the month parameter is evaluated
Use comparison operators with date valuesYou can use the following comparison operators to compare date values in expressions and in queries:
- < (less than)
- > (greater than)
- <= (less than or equal to)
- >= (greater than or equal to)
- <> (not equal)
This query uses the >= comparison operator and the <= comparison operator to
verify whether the hire date of the employee falls in the range of the two
specified dates. This query fetches the records of all employees who were hired in
the last quarter of the calendar year 1993.
SELECT * FROM Employees
WHERE HireDate >= DateValue(" 10/01/1993")
AND HireDate <= DateValue("12/31/1993");
This query uses the inequality comparison operator to fetch the
records of all employees who have a hire date that is not equal to the current
SELECT * FROM Employees
WHERE HireDate <> Date();
The WeekdayName() function returns a string that indicates the
day of the week, as specified in the first parameter. The day of the week string that is returned depends on the third parameter. This parameter sets the first day of the week. The second parameter is set to False to specify that the weekday name must not be abbreviated.
SELECT WeekdayName(1, False, 1) AS FirstWeekDayName;
This example query returns the value Sunday as the first day of the week.
MonthName() functionThe MonthName() function returns a string that indicates the month name
for the specified month number from 1 through 12. The input parameter can also be an
expression, as in the following query:
This query returns the name of the current month.
SELECT MonthName( DatePart("m", Date()) );
For more information, click the following article numbers to view the articles in the Microsoft Knowledge Base:
How to create a query that has parameters to evaluate complex criteria in Microsoft Access
How to create two functions to calculate age in months and in years in Microsoft Access
Article ID: 826766 - Last Review: March 28, 2007 - Revision: 3.1
- Microsoft Office Access 2007
- Microsoft Office Access 2003
- Microsoft Access 2002 Standard Edition
|kbdownload kbfunctions kbdatetime kbvalidation kbquery kbdatabase kbinfo KB826766||