CPD3 Time Format

In general a time specification accepts most ISO8601 formats in addition to a number of auxiliary formats.

The literal now

The current time.

An infinite bound

This is one of the following forms:

Empty: All space or zero length.
0: The number zero.
none
undef or undefined
inf or infinity
all
forever

An integer and an offset multiplier

This offsets the time in the other reference point. It is only valid when a reference point exists, such as valid other bound in a pair of times. The form is of "X<unit>" where "X" is a non-negative number, and "<unit>" is one of:

msec or milliseconds
s, sec, or seconds
m, min, or minutes: Exactly X * 60 seconds.
h or hours: Exactly X * 3600 seconds.
d or days: Exactly X * 86400 seconds.
w or weeks: Exactly X * 604800 seconds.
mo, mon, or months: Preserves the time of day and day of month.
q, qtr, or quarter: Preserves the time after the start of the quarter.
y or years: Preserves the month, day of month, and time of day.

Example 1. One week from the reference point

The offset may also also be followed by a or aligned to align to the boundary the multiplier represents.

Example 2. Rounding to the quarter boundary

0qa

In general the count must be an integer. However, decimal numbers are accepted for the exact fixed length specifications and are interpreted as the largest whole unit below the specification that gives the exact time.

Example 3. 36 hours as a number of days

1.5d

Alignment is not allowed on fractional specifications. Without the alignment enabled, the count number must be positive (non-zero). If the count is omitted then the specification is for a single of the unit.

Date and/or time

If present the date must come first. The date must start with a four digit year, followed by an optional month and day of month. Each field must be separated by either a dash or a slash. The time then follows either a space separator or a T. Time is specified on a 24 hour clock, with the hours first, seconds being optional. Each field must be separated by a :. The specification may optionally end in a Z.

Example 4. ISO8601 specification

2010-03-10T00:15:00Z

Example 5. Excel-like specification

2010/03/10 00:15:00

Example 6. Date only

2010-03-10

Example 7. Date and time without delimiters

20100310T001500Z

Example 8. Time only

15:00:12.123Z

Example 9. Year only

2010

If only a time is specified, the date is inferred from the reference point such that it would be reasonable relative to it.

Example 10. Data inference

If the this is the start bound and the time is after the reference end bound, then it is assumed to be in the prior day

A date and/or time may optionally be followed by a time zone offset. This takes the form of plus or minus and a two or four digit integer or hh:mm. This number is subtracted or added to the given time to give UTC.

Year and week or week

One of the following forms:

YYYYwWW
YYYYwWW-D: Monday is day one.
wWW
wWW-D: Monday is day one.

Note that the "WW" component may be a single digit. The exact time that the week specifies depends on the reference point: if this is a start bound, then time specified is the start of that week, otherwise it is the end. If the year is omitted then it is inferred from the reference point as with only a time above.

Year and quarter or quarter

One of the following forms:

YYYYqQ
qQ

The exact time that the quarter specifies depends on the reference point as above with weeks.

Year and DOY or DOY

A four digit year separated from a DOY by any of :, ;, , or space(s). The day of year starts with 1.0 being midnight January 1st of that year. The separator may also be omitted or replaced with - if there are exactly three digits in the integer component of the DOY. If the DOY has exactly two decimal digits, it is assumed to specify an hour and rounded to the nearest hour boundary.

Example 11. Midnight January 1st, 2010

2010:1

Example 12. 0600 January 2nd, 2010

2010,1.25

Example 13. 1200 January 23, 2010

2010;023.5000

2010023.5000

Example 14. Midnight January 27, 2010

2010-027

The year may also be omitted in which case it is inferred from the reference point.

A fractional year

This is a number with a fractional component between 1900.0 and 2999.0. The integer part is interpreted as a year and the fractional part is the fraction of the way through the year.

Example 15. Fractional year at 2010-01-01T00:00:00Z

2010.0

Example 16. Fractional year at 2010-07-02T12:00:00Z

2010.5

An epoch time

This is a decimal number of seconds since 1900-01-01T00:00:00Z. This may also be begun with E: to disambiguate from ISO time strings.

The time specification may be followed by an offset, this consists of a plus or minus, an integer, and a unit. The integer number of the given time unit are added or subtracted to the time specified before. The following time units are valid:

msec or milliseconds
s, sec, or seconds
m, min, or minutes: Exactly X * 60 seconds.
h or hours: Exactly X * 3600 seconds.
d or days: Exactly X * 86400 seconds.
w or weeks: Exactly X * 604800 seconds.
mo, mon, or months: Preserves the time of day and day of month.
q, qtr, or quarter: Preserves the time after the start of the quarter.
y or years: Preserves the month, day of month, and time of day.

Example 17. Five day offset

2010-03-10T00:15:00Z+5d is equivalent to 2010-03-15T00:15:00Z.

Note	Overflow When the alignment would overflow a date field it is set to the largest valid one in the alignment. So one month up from Mar 31 would be on Apr 30.