A time interval.

Input Format:

This is a sexagesimal style format, with suffixes after each component to allow one to enter just the components that meet your requirements. The following are a few examples of valid intervals, followed by their meanings:

  23d:14h:16m:2.32s   ->  23 days, 14 hours , 16 minutes, 2.32 seconds.
  15.5m               ->  15 minutes, 30 seconds..
  100h                ->  110.h hours.
  4m:2.5s             ->  4 minutes, 2.5 seconds.
 -2h                  ->  -2 hours (negative intervals are mainly used for
                                    specifying do-loop increments).

Any of the components can be omitted, but they must appear in order of decreasing significance.

The first of the chosen components can have a sign, and the last component can have a fractional part.

Note that it is an error for the value of one component to exceed one unit of the component that precedes it. Thus 23d:300m is ok because there are more than 300 minutes in a day, but 23d:4h:300m isn't, because an hour component has been provided and 300 minutes exceeds the number of minutes in an hour.

Use with do-loops:

When an Interval variable is used as the dependent variable of a do-loop, the associated loop increment is also specified as an Interval.

Example 1:

The following three lines are equivalent. Each prints the value 23h:30m:27.0s.

 print $Interval(23.5075h)

 print $Interval(23h:30.45m)

 print $Interval(23h:30m:27s)

Example 2:

The following example halts script execution for 1.5 hours.

 until $elapsed >= 1h:30m

Example 3:

The following example would show the position of the source 3c286 in two and a half days time.

 show 3c286, utc=$date + 2.5d

or equivalently:

 show 3c286, utc=$date + 2d:12h

Context:

There are two common uses of time intervals. They are used in Date expressions to add or subtract from a given date and time. They are also used by the elapsed() function to specify how long the function should return false after entering its enclosing loop or until statement.