A time variable is required for all forecasting projects. See Understanding Time Intervals for more information about the other settings for the time variable.
If a single candidate time variable is detected in your data source, it is automatically selected. If multiple candidates are detected, you must choose one.
Select the time interval that you want to use to collect the data. For each time interval, you can specify the type (such as monthly or weekly), a multiplier, and a shift (the offset for the interval). You can specify a greater time interval than that found in the input data. Smaller intervals generate a large number of observations and should be avoided. Each time interval has its own Shift interval setting and some have specific starting subintervals. For example, by default, a weekly time interval starts on Sunday (Shift = 1), which you can change to another starting day of the week using the Shift setting.
Choose from the following options:
specifies second intervals. The shift interval is in seconds.
specifies minute intervals. The shift interval is in minutes.
specifies hourly intervals. The shift interval is in hours.
specifies daily intervals. The shift interval is in days.
specifies daily intervals with weekend days included in the preceding weekday. The weekday interval is the same as the day interval, except that the weekend days are absorbed into the preceding weekday. The default weekend days are Saturday and Sunday. There are five weekday intervals in the default calendar week: Monday, Tuesday, Wednesday, Thursday, and the three-day period Friday, Saturday, and Sunday. The shift interval is in weekdays.
specifies weekly intervals of seven days. The shift interval is days with the starting subinterval on Sunday.
The days of the week are numbered by the Shift setting as follows:
|
Value of the Shift |
Day of the Week |
|---|---|
|
1 |
Sunday |
|
2 |
Monday |
|
3 |
Tuesday |
|
4 |
Wednesday |
|
5 |
Thursday |
|
6 |
Friday |
|
7 |
Saturday |
specifies ISO 8601 weekly intervals of seven days. The shift interval is days with the starting subinterval on Monday.
specifies 10-day intervals. Each month consists of three periods. The first period is the 1st through the 10th day of the month. The second period is the 11th through the 20th day of the month. The third period is the 21st through the end of the month. The shift interval is 10-day periods.
specifies semimonthly intervals. SEMIMONTH breaks each month into two periods, starting on the first and 16th days. The shift period is in semimonthly intervals.
specifies monthly intervals. The shift interval is in months.
specifies retail 4-4-5 monthly intervals. The 3rd, 6th, 9th, and 12th months are five ISO 8601 weeks long with the exception that some 12th months contain leap weeks. All other months are four ISO 8601 weeks long. R445MON intervals begin with the 1st, 5th, 9th, 14th, 18th, 22nd, 27th, 31st, 35th, 40th, 44th, and 48th weeks of the ISO year. The shift interval is in retail 4-4-5 months.
specifies retail 4-5-4 monthly intervals. The 2nd, 5th, 8th, and 11th months are five ISO 8601 weeks long. All other months are four ISO 8601 weeks long with the exception that some 12th months contain leap weeks. R454MON intervals begin with the 1st, 5th, 10th, 14th, 18th, 23rd, 27th, 31st, 36th, 40th, 44th, and 49th weeks of the ISO year. The shift interval is in retail 4-5-4 months.
specifies retail 5-4-4 monthly intervals. The 1st, 4th, 7th, and 10th months are five ISO 8601 weeks long. All other months are four ISO 8601 weeks long with the exception that some 12th months contain leap weeks. R544MON intervals begin with the 1st, 6th, 10th, 14th, 19th, 23rd, 27th, 32nd, 36th, 40th, 45th, and 49th weeks of the ISO year. The shift interval is in retail 5-4-4 months.
specifies quarterly intervals (every three months). The shift interval is in months.
specifies retail 4-4-5 quarterly intervals (every 13 ISO 8601 weeks). Some fourth quarters will contain a leap week. The shift interval is in retail 4-4-5 months.
specifies retail 4-5-4 quarterly intervals (every 13 ISO 8601 weeks). Some fourth quarters will contain a leap week. The shift interval is in retail 4-5-4 months.
specifies retail 5-4-4 quarterly intervals (every 13 ISO 8601 weeks). Some fourth quarters will contain a leap week. The shift interval is in retail 5-4-4 months.
specifies intervals every six months. The shift interval is in months.
specifies yearly intervals. The shift interval is in months.
specifies ISO 8601 yearly intervals. The ISO 8601 year starts on the Monday on or immediately preceding January 4 (or on January 4 if it is a Monday). Note that it is possible for the ISO 8601 year to start in December of the preceding year. Also, some ISO 8601 years contain a leap week. For more information about ISO weeks, see Technical Committee ISO/TC 154 (Processes, Data Elements, and Documents in Commerce, Industry, and Administration) (2004). The shift interval is in ISO 8601 weeks (WEEKV).
is the same as YEARV except that the shift interval is in retail 4-4-5 months.
is the same as YEARV except that the shift interval is in retail 4-5-4 months
is the same as YEARV except that the shift interval is in retail 5-4-4 months
Specify an integer that is used to multiply the time interval for customizing the interval. For example, if time interval is set to MONTH and multiplier is 2, then the interval used by the project is every two months. This value can be any positive number.
Specify an integer to shift the starting point for the day that the interval begins. Specify the starting point for the interval. By default, this value is 1. A value greater than 1 shifts the start to a later point within the interval. The unit for the shift depends on the interval. For example, if shift is set to 4 and the time interval is YEAR, this shifts the start of the time interval to the fourth month. In this case, a year is from April 1 through March 31 of the following year. The starting point is dependent on the interval.
For a list of default starting points for each interval, see Time Interval, Multiplier, and Shift Examples.
Specify the length of a season in the units set by the time interval. This value is populated automatically if SAS Visual Forecasting can determine the seasonal cycle length from the time variable. However, you can specify a seasonal cycle length other than the default if you want to model a cycle in the data. For example, your data might contain a 13-week cycle, so you need to specify a 13-week seasonal cycle length in SAS Visual Forecasting.