Reference to the dayOfYear() function

Summary

dayOfYear(<timeZone>)

Returns the day of the year in the specified time zone.

Parameters

ParameterDescription
timeZone String identifier or alias for a time zone, such as "US/Pacific". Names are case sensitive and must be enclosed in quotes. For a list of valid time zone identifiers and their aliases, see http://joda-time.sourceforge.net/timezones.html.

Description

The dayOfYear() standard time function returns the day of the year in the specified time zone. A day is represented as a whole number from 1 through 366, as defined by the Gregorian calendar. 366 is returned only during a leap year.

The returned values are plotted against the times shown on the x-axis. The returned series is generally a straight line, unless you are looking at a chart that includes times from multiple days. dayOfYear() automatically adjusts its return values for daylight savings time.

dayOfYear() is particularly useful when you want to define an alert that fires only on a specific day or range of days within a year, such as a range that starts in the middle of a month and includes multiple weeks or months. For example, you could use an expression such as between(dayOfYear("America/Chicago"),304,359) in an alert condition to ensure that the alert fires only between Halloween and Christmas in a non-leap year in Central Standard Time.

dayOfYear() does not automatically accommodate leap years. You can use the lead() function in an expression such as the following to return 1 on the last day of the year for a given time zone, regardless of whether the year is a leap year: lead(1d, dayOfYear(...)=1).

Examples

Example 1: Showing Days of the Year

This chart shows live data for 8 days. dayOfYear("America/Chicago") returns 161 through 169, representing the 161st through the 169th days of the current year. The legend shows that 163 is returned for June 12, 2018. dayOfYear

Example 2: Defining an Alert that Fires on Particular Days

Here we include (dayOfYear("America/Chicago") = 163) in a conditional expression to define an alert that fires when the CPU load average rises above 2.5 on the 163rd day of the year. dayOfYear alert

See Also

weekday() Function

day() Function