Visual Basic for Applications (VBA) is a programming language used in Microsoft Office applications to automate tasks and enhance functionality. One of the built-in functions in VBA is CDate, which stands for “Convert to Date”. As the name suggests, the CDate function is used to convert a value into a date data type. It takes an input and converts it into a date variable, which can then be manipulated and used in various operations.
VBA CDate Function – Purpose, Syntax and Arguments
Purpose
The primary purpose of the CDate function is to convert non-date values into a date data type so that they can be used in date calculations, comparisons, and other operations. This can be particularly useful when working with data that is stored as text, but needs to be treated as dates. The CDate function also allows users to convert date values from one format to another, such as from a text string to a date format recognized by VBA.
Syntax
CDate(expression)
The expression argument in the CDate function can be any valid VBA expression that evaluates to a value. This argument is required, and it can be a numeric, date, or text value. It can also be a variable, user-defined function, or an operator.
Arguments
The expression argument in the CDate function is required and can be any valid VBA expression. Some important points to remember about the expression argument are:
- The expression can be a text string enclosed in double-quotes, a number, or a date value enclosed in hash symbols (#).
- If the expression is a text string, it must be in a format that can be interpreted as a date by VBA, such as “mm/dd/yyyy”.
- If the expression is a number, it must be a valid date serial number recognized by VBA (see Example section below).
- If the expression is a date, it must be in a format that VBA recognizes as a valid date, such as #mm/dd/yyyy#.
Example
Let’s take a look at an example to understand how the CDate function works. In this example, we have a list of dates in the format “mm/dd/yyyy” stored as text. We want to add 30 days to each date and display the result. However, since the dates are stored as text, we need to convert them to date format using the CDate function before performing the calculation.
Sub ConvertToDates()
Dim startDate As String
Dim endDate As String
Dim newDate As Date
Dim i As Long
startDate = "01/01/2021"
endDate = "01/31/2021"
For i = CDate(startDate) To CDate(endDate)
newDate = DateAdd("d", 30, i)
MsgBox "Date after adding 30 days: " & newDate
Next i
End Sub
In this code, we first declared two variables startDate and endDate as strings to store the start and end dates. We then used the for loop to loop through all the dates between the two values, which were converted to date format using the CDate function. In each iteration, we used the DateAdd function to add 30 days to the current date and displayed the result using the MsgBox function.
Remarks and Important Notes
- The return type of the CDate function is always a date data type.
- If the expression argument cannot be converted into a date, an error will be returned.
- The accepted date format by VBA may vary depending on the regional settings of the computer.
- The CDate function can also be used to convert date values from one format to another. For example, CDate(“01/01/2021”) will return a date value, while CDate(“01-01-2021”) will return an error.
- The CDate function is often used in conjunction with other date functions, such as DateAdd and DateDiff, to manipulate and perform calculations on dates.
Understanding VBA CDate Function with Examples
Visual Basic for Applications (VBA) is a programming language commonly used in Microsoft Office applications such as Excel, Word, and Access. It allows users to automate tasks and create custom solutions to make their work more efficient. One of the key functions in VBA is the CDate function, which converts a given expression into a Date data type. In this blog post, we will explore the CDate function and its various applications through examples.
Basic Syntax
Description:
The basic syntax for the CDate function is CDate(expression), where the expression can be any valid date or time format.
Code:
Dim dateValue As Date
dateValue = CDate("12/31/2021")
MsgBox dateValue
Explanation:
In this example, we first declare a variable dateValue of data type Date. We then use the CDate function to convert the string “12/31/2021” into a Date data type and assign it to the variable dateValue. Finally, we use the MsgBox function to display the date value in a message box. The result will be 12/31/2021.
Using Variables as Expressions
Description:
The CDate function can be used with variables, making it possible to convert a date or time value stored in a variable into a Date data type.
Code:
Dim timeValue As String Dim dateValue As Date timeValue = "1:00 PM" dateValue = CDate(timeValue) MsgBox dateValue
Explanation:
In this example, we first declare two variables – timeValue as a string and dateValue as a Date. We then assign the string “1:00 PM” to the variable timeValue. This value is then converted into a Date data type using the CDate function and stored in the variable dateValue. Finally, the date value is displayed in a message box, which will be 1:00 PM.
Converting Dates with Different Formats
Description:
The CDate function is versatile and can convert date and time values in a variety of formats, including different separators and order of day, month, and year.
Code:
Dim dateValue As Date
dateValue = CDate("31-12-2021")
MsgBox dateValue
Explanation:
In this example, we have used the date format “DD-MM-YYYY”, which is different from the default date format in VBA, “MM/DD/YYYY”. However, the CDate function is still able to convert the given value into a Date data type and display it in the message box as 12/31/2021.
Using Date Functions as Expressions
Description:
The CDate function can also be used with other date functions in VBA, making it possible to perform calculations and manipulations on dates.
Code:
Dim dateValue1 As Date
Dim dateValue2 As Date
dateValue1 = CDate(Date)
dateValue2 = CDate(DateAdd("d", 30, Date))
MsgBox dateValue1 & vbNewLine & dateValue2
Explanation:
In this example, we have used two nested CDate functions. The first one converts the current date into a Date data type using the Date function, while the second one uses the DateAdd function to add 30 days to the current date and then converts it into a Date data type using the CDate function. The result will be two different date values – one for the current date and one for 30 days later – separated by a new line in the message box.
Handling Input Errors
Description:
When using the CDate function, it is important to handle potential input errors, such as invalid or blank values.
Code:
Dim dateValue As Date
On Error Resume Next
dateValue = CDate("apple")
If Err.Number = 0 Then
MsgBox dateValue
Else
MsgBox "Invalid Date"
End If
Explanation:
In this example, we have used the On Error Resume Next statement to ignore any errors that may occur while converting the value “apple” to a Date data type. If the conversion is successful, the date value will be displayed in a message box. However, if there is an error, the Err.Number value will be non-zero, and the program will display an error message instead of trying to display an invalid date value.
Conclusion
In this blog post, we have explored the CDate function in VBA and its various applications. We have seen how this function can convert a given expression into a Date data type and handle different date and time formats. By understanding how to use the CDate function, users can perform complex calculations and manipulate date values in their VBA projects.
