Convert a Date into a DateTime Variable

Convert a Date into a DateTime Variable

In SAS exist Date and DateTime variables. If you want to compare them, they should be of the same type. This article explains how to transform a Date variable into a DateTime variable with the DHMS function. The article also contains some useful examples.

The DHMS syntax

DHMS(date, hour, minute, second)

The DHMS function exists of four obligatory arguments:

• date: This is the date part of the DateTime variable.
• hour: The hour of the DateTime variable.
• minute: The minute of the DateTime variable.
• second: The second of the DateTime variable.

All arguments can be existing variables or numbers. Besides that, the date argument can also be a constant that can be interpreted by SAS as a date (see example).

SAS Code & Examples

Below you find an example of how to convert a Date variable into a DateTime variable. The example also shows how to create a DateTime variable where the date argument is a constant that SAS interprets as a Date.

DATA WORK.DS;
	SET SASHELP.BUY (DROP= AMOUNT);
	
	/* CREATE DATETIME VARIABLES */
	MY_DATETIME_12PM = DHMS(DATE,0,0,0);
	MY_DATETIME_1630 = DHMS(DATE,16,30,0);
	
	/* CREATE DATETIME VARIABLE */
	MY_DATETIME = DHMS("15JUN2020"D,22,30,00);
	
	/* FORMAT DATETIME VARIABLES */
	FORMAT MY_DATETIME: DATETIME20.;
RUN;

Remember, since both Date and DateTime variables in SAS are in fact numbers, it’s necessary to format the new variables to make them easier to interpret.

The official SAS documentation of the DHMS functions can be found here. Also, see this example to convert a DateTime variable into a Date variable.