Clarion Community Help

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
| **Navigation:**  [[introduction.htm|Language Reference]] > 3 - Variable Declarations > Data Types >====== DATE (four-byte date) ====== | [[implicit string arrays and string slicing.htm|{{btn_prev_n.gif|Previous page}}]][[introduction.htm|{{btn_home_n.gif|Return to chapter overview}}]][[time  four byte time .htm|{{btn_next_n.gif|Next page}}]] |
|  ||

| label | **DATE** | [,**DIM( )**] [,**OVER( )**] [,**NAME( )**] [,**EXTERNAL**] [,**DLLL**] [,**STATIC**] [,**THREAD**] [,**AUTO**] [,**PRIVATE**] [,**PROTECTED**] |
|  |  |  |

{{blk2blue.jpg|blk2blue.jpg}}

| **DATE** | A four-byte date. |

**Format:    year      mm     dd **

**       | ........ | .... | .... | **

**Bits: 31         15      7      0**

**Range:**

**year:  1 to 9999**

**month: 1 to 12**

**day:   1 to 31**

| **DIM** | Dimension the variable as an array. |
| **OVER** | Share a memory location with another variable. |
| **NAME** | Specify an alternate, "external" name for the field. |
| **EXTERNAL** | Specify the variable is defined, and its memory is allocated, in an external library. Not valid within FILE, QUEUE, or GROUP declarations. |
| **DLL** | Specify the variable is defined in a .DLL. This is required in addition to the EXTERNAL attribute. |
| **STATIC** | Specify the variable's memory is permanently allocated. |
| **THREAD** | Specify memory for the variable is allocated once for each execution thread. Also implicitly adds the STATIC attribute on Procedure Local data. |
| **AUTO** | Specify the variable has no //initial value//. |
| **PRIVATE** | Specify the variable is not visible outside the module containing the CLASS methods. Valid only in a CLASS. |
| **PROTECTED** | Specify the variable is not visible outside base CLASS and derived CLASS methods. Valid only in a CLASS. |

**DATE** declares a four-byte date variable. This format matches the "DATE" field type used by the Btrieve Record Manager. A DATE used in a numeric expression is converted to the number of days elapsed since December 28, 1800 (Clarion Standard Date - usually stored as a LONG). The valid Clarion Standard Date range is January 1, 1801 through December 31, 9999. Using an out-of-range date produces unpredictable results. DATE fields should be used to achieve compatibility with outside files or procedures.

**Example:**

<code>
DueDate     DATE                      !Declare a date field
OtherDate   DATE,OVER(DueDate)        !Declare field over date field
ContactDate DATE,DIM(4)               !Array of 4 date fields
ExampleFile FILE,DRIVER('Btrieve')    !Declare a file
Record       RECORD
DateRecd       DATE,NAME('DateField') !Declare with external name
            END
           END
</code>

While a DATE data type has a unique long integer internal D-M-Y format any code using it will automatically convert it to or from a Clarion Standard Date. The only way to obtain the DATE in internal format must be done with a LONG or STRING over the DATE. In the below example code the number 5 is the standard date for Jan, 2 1801.

<code>
BT_Date  DATE
BT_Raw   LONG,OVER(BT_Date)  !Obtain DATE in internal format
 BT_Date = 5
 Message(Format(BT_Date,@d8-) &' - '& BT_Date &' - '& BT_Raw )
 !displays: 2-Jan-1801 - 5 - 118030594
 !118030594 => 07090102h  0709h => 1801
</code>

**Additional Example:**

<code>
!Extracts date parts w/o multiple calls to MONTH,DAY,YEAR or using FORMAT() and slicing.
GetMDY  PROCEDURE(LONG ClaDate, *LONG OutMonth, *LONG OutDay, *LONG OutYear)
BTDate  DATE,AUTO
BT      GROUP,OVER(BTDate)  !Note Little Endian reversal
Day      BYTE
Month    BYTE
Year     USHORT
       END
 CODE
 BTDate = ClaDate ! Convert LONG (Clarion Standard Date) to a Btrieve date DDMMYYYY
 OutMonth = BT.Month
 OutDay   = BT.Day
 OutYear  = BT.Year
 RETURN
</code>

**See Also:**

[[standard date.htm|Standard Date]]
[[time  four byte time .htm|TIME]]