# The time operator

The time operator returns with the time in seconds of the data samples.
```  Usage:
p0y = time(q0)
```

To see the time Dialog window mark the time with the left mouse button in the input text line in the igr calculator window.
Then press Edit->Operator. Now the time Dialog window appears.

The user use the time dialog window to selecet options for the time operator:

t(n)-'TIME'
This is the default mode of the time operator.

In this case the user write in the igr calculator:
pny = time(qm,'YYYY-MM-DDTHH:mm:ss.sZ')
If the 'YYYY-MM-DDZHH:mm:ss.sZ' is not written 1970-01-01T00:00:00.0Z is used.
In this mode the operator returns the time of the data sample in seconds minus 'YYYY-MM-DDTHH:mm:ss.sZ'

Example:
p0y = time(q0,'2011-12-03T07:21:31.0Z')
In this case the operator returns with the time of the data sample in seconds since 3 Dec 2011, 07:21:31 UT
t(n)- t(0)
In this case the time operator returns with the time of the data sample in seconds minus the time of the first sample.

t(n)- t(n-1)
In this case the time operator returns with the time of the data sample in seconds minus the time of the previous sample.
The operator returns with the time between the data samples.

t(n)- 2t(n-1)+t(n-2)
In this case the time operator returns with the time of the data sample in seconds, minus twice the time of the previous sample, pluss the time of sample before that.

'sec of day'
In this case the time operator returns with the time of the data sample minus the time of midnight.

n
In this case the time operator returns with data sample number. (This option do not returns with the time.)

undef
In this option the time operator has no effect.

Updated Aug 22, 2012 by Bjørn Lybekk