TIME Axes :: SAS(R) 9.3 Graph Template Language: User's Guide

Overview of TIME Axes

TIME axes are numeric axes that display SAS date or time values in an intelligent way. Such axes are created whenever the primary plot has a SAS date, time, or datetime format associated with a column that is mapped to an axis. In the following example, the DATE variable has a SAS date format associated with it. By default, the TIME axis decides an appropriate tick value format and an interval to display. Notice that, in the default case, when the X or X2 axis is a TIME axis, the space that is used for the tick values is conserved by splitting the values at appropriate date or time intervals and extracting larger intervals. In this example, the column format for the DATE variable could be MMDDYY or any other date-type format. The actual format serves only as a hint and is not used directly, unless requested.

layout overlay; 
  seriesplot x=date y=close;
endlayout;

Note: In this example, the data range for DATE was from 1Jan2004 to 1Dec2005. The TIME axis chose the interval of MONTH to display tick values. Had the data range been larger, say 1Jan1998 to 1Dec2005, the TIME axis would choose a larger interval, YEAR, to display by default.

Setting the Tick Values

Using the INTERVAL= option, you can select different date or time intervals to display. The default interval is AUTO, which chooses an appropriate interval, based on the data and the column format.

Value on INTERVAL=	Unit	Tick Interval	Default Tick Value Format
AUTO	DATE, TIME, or DATETIME	automatically chosen	automatically chosen
SECOND	TIME or DATETIME	second	TIME8.
MINUTE	TIME or DATETIME	minute	TIME8.
HOUR	TIME or DATETIME	hour	TIME8.
DAY	DATE or DATETIME	day	TIME9.
TENDAY	DATE or DATETIME	ten days	TIME9.
WEEK	DATE or DATETIME	seven days	TIME9.
SEMIMONTH	DATE or DATETIME	1st and 16th of each month	TIME9.
MONTH	DATE or DATETIME	month	MONYY7.
QUARTER	DATE or DATETIME	three months	YYQC6.
SEMIYEAR	DATE or DATETIME	six months	MONYY7.
YEAR	DATE or DATETIME	year	YEAR4.

The following example specifies that tick values should occur at quarter intervals:

layout overlay / xaxisopts=( timeopts=(interval=quarter) );

By default, the tick values are split to conserve space when possible. The following table shows the rules for tick value splitting.

Original Form	Split Form
DAY-MONTH-YEAR	DAY-MONTH YEAR
QUARTER-YEAR	QUARTER YEAR
MONTH-YEAR	MONTH YEAR
TIME-DATE	TIME DATE
TIME only	original form
YEAR, QUARTER, MONTH, or DAY only	original form
International format	original form

You can turn off the splitting feature with the SPLITTICKVALUE=FALSE option. Notice that each tick value uses more space.

layout overlay / xaxisopts=(timeopts=(interval=quarter
                                      splittickvalue=false ));

Formatting Axis Tick Values

As with LINEAR axes, you can force a specific format for tick values with the TICKVALUEFORMAT= option, which also turns off the tick splitting feature. If you specify TICKVALUEFORMAT=DATA, the format is associated with the column that is used. Or you can specify a format:

layout overlay / xaxisopts=(timeopts=(interval=semiyear
                                      tickvalueformat=monyy. ));

Avoiding Tick Value Collisions

As with LINEAR axes, you can specify a tick value fitting policy for a TIME axis. The following policies are available: THIN, ROTATE, STAGGER, ROTATETHIN, STAGGERTHIN, and STAGGERROTATE when tick values are not split. The default policy is THIN .

layout overlay / xaxisopts=(timeopts=(interval=month 
                                      splittickvalue=false
                                      tickvaluefitpolicy=rotate ));

For information about the tick value fit policies that can be used with a time axis in each of the applicable layouts, see Tick Value Fit Policy Applicability Matrix.

Setting the Axis Data Range

As with LINEAR axes, you can force specific tick values to be displayed with the TICKVALUELIST= option. The VIEWMIN= and VIEWMAX= options control the data range of the axis. If you specify TICKVALUEFORMAT=DATA, the format that is associated with the column is used.

layout overlay / xaxisopts=(timeopts=( tickvalueformat=data
  viewmin="31Dec2002"d viewmax="31Dec2004"d
  tickvaluelist=("31Dec2002"d "30Jun2003"d
                 "31Dec2003"d "30Jun2004"d "31Dec2004"d) ));

Axis with TICKVALUELIST=, VIEWMIN=, and VIEWMAX=