Examples of Interval Specifications

Table 4.1 shows examples of different kinds of interval specifications.

Table 4.1: Examples of Intervals

Name

Description of Interval

YEAR

Years that start in January

YEAR.10

Years that start in October

YEAR2.7

Biennial intervals that start in July of even years

YEAR2.19

Biennial intervals that start in July of odd years

YEAR4.11

Four-year intervals that start in November of leap years (frequency of U.S. presidential elections)

YEAR4.35

Four-year intervals that start in November of even years between leap years (frequency of U.S. midterm elections)

YEARV

Years that start on the Monday on or immediately preceding January 4th

YEARV.2

Years that start on the Monday immediately following January 4th

R445MON

Months that start on the $1$st, $5$th, $9$th, $14$th, $18$th, $22$nd, $27$th, $31$st, $35$th, $40$th, $44$th, and $48$th Monday of the year. The $1$st Monday is the Monday on or immediately preceding January 4th

R445MON3

Three-month intervals that start on the $1$st, $14$th, $27$th, and $40$th Monday of the year. This is equivalent to R445QTR

R445MON3.2

Three-month intervals that start on the $5$th, $18$th, $31$th, and $44$th Monday of the year. This is equivalent to R445QTR.2

WEEK

Weekly intervals that start on Sundays

WEEK2

Biweekly intervals that start on first Sundays

WEEK1.1

Same as WEEK

WEEK.2

Weekly intervals that start on Mondays

WEEK6.3

Six-week intervals that start on first Tuesdays

WEEK6.11

Six-week intervals that start on second Wednesdays

WEEKDAY

Daily with Friday-Saturday-Sunday counted as the same day (five-day work week with a Saturday-Sunday weekend)

WEEKDAY17W

Same as WEEKDAY

WEEKDAY5.2

Five weekdays that start on Monday. If WEEKDAY data are accumulated into weekly data, the interval of the accumulated data is WEEKDAY5.2

WEEKDAY67W

Daily with Thursday-Friday-Saturday counted as the same day (five-day work week with a Friday-Saturday weekend)

WEEKDAY1W

Daily with Saturday-Sunday counted as the same day (six-day work week with a Sunday weekend)

WEEKDAY3.2

Three-weekday intervals (with Friday-Saturday-Sunday counted as one weekday) with the cycle three-weekday periods aligned to Monday, January 4, 1960

HOUR8.7

Eight-hour intervals that start at 6 a.m., 2 p.m., and 10 p.m. (might be used for work shifts)