DT_TO_SEC Function
Standard Library function that converts a date/time variable to a double-precision variable containing number of seconds elapsed from a base date.
Usage
-
result = DT_TO_SEC(dt_var)
Input Parameters
dt_var — A date/time variable.
Returned Value
result — A double-precision variable containing the number of seconds elapsed between the base date and the date(s) contained in dt_var. The value of the base date is maintained in the system variable !DT_Base.
Keywords
Base — A string containing a date, such as “3-27-92”. This is the base date from which the number of elapsed seconds is calculated. Base can be used to override the default value in the system variable !DT_Base.
Date_Fmt — Specifies the format of the base date, if passed into the function. Possible values are 1, 2, 3, 4, or 5, as summarized in Possible Date_Fmt Values:
|
Value |
Format Description |
Examples for May 1, 1992 |
|
1 |
MM*DD*[YY]YY |
05/01/92 |
|
2 |
DD*MM*[YY]YY |
01-05-92 |
|
3 |
ddd*[YY]YY] |
122,1992 |
|
4 |
DD*mmm[mmmmmm]*[YY]YY |
01/May/92 |
|
5 |
[YY]YY*MM*DD |
1992-05-01 |
where the asterisk (*) represents one of the following separators: dash (–),
slash (/), comma (,), period (.), or colon (:).
For a detailed description of these formats, see the PV‑WAVE User Guide.
Discussion
This function is useful for converting date/time values to relative time. The default base date is September 14, 1752.
Example 1
Assume that you have created the array date1 that contains the following date/time data:
date1 = [{!DT, 2002,3,27,7,18,57.0000,91140.305,0},$
{!DT, 2003,3,27,7,18,57.0000,91505.305,0}, $
{!DT, 2004,3,27,7,18,57.0000,91871.305,0}]
; To find out the number of seconds for each date from
; the default base, September 14, 1752, use:
seconds = DT_TO_SEC(date1)
PRINT, seconds, Format='(F15.1)'
; PV-WAVE prints:
; 7874435937.0
; 7905971937.0
; 7937594337.0
Example 2
Assume that you have created the array date1 that contains the following date/time data:
date1 = [{!DT, 2002,3,27,7,18,57.0000,91140.305,0},$
{!DT, 2003,3,27,7,18,57.0000,91505.305,0}, $
{!DT, 2004,3,27,7,18,57.0000,91871.305,0}]
; To find out the number of seconds for each date from
; January 1, 1970, use:
seconds = DT_TO_SEC(date1, Base='1-1-70', Date_Fmt=1)
PRINT, seconds, Format='(F15.1)'
; PV-WAVE prints the following:
; 1017213537.0
; 1048749537.0
; 1080371937.0
See Also
DT_TO_STR, DT_TO_VAR, SEC_TO_DT
System Variables: !DT_Base
For more information, see the PV‑WAVE User Guide.
