## Splitting time variables

Use this software if you wish to extract individual time/date fields from a variable in the data which contains multiple time/date values; eg, you'd like a year variable, a month variable, and a date variable, and there is a variable which contains all 3.

Use the time conversion software if you'd like to change Gregorian data to Julian data, local time/date to UTC, etc.

variable name input

Supply the name of the variable with the multiple times. The software may take a guess, but any variable may be selected.

The variable with the multiple times must be in fixed format (eg, this software can NOT be used to split dates encoded like "January2001","February2001",...)

If you need to split more than one variable, split one, then re-enter the time splitter via the "Plotting and Other Options" link in the same way you got to the time splitter in the first place.

format input

The format describes the data for the selected variable

    Acceptable "pieces" of the format are
    	yyyy or yy	for year (yy is interpreted in the range 1950-2049)
    	mm or mmm	for month (mmm is interpreted as a 3-letter
    				   month abbreviation (eg, Jan))
    	dd		for day of month
    	HH		for hour (HH takes values from 00 to 23)
    	MM		for minute
    	jjj or JJJ	for day of year (J if Jan 1 = 0; j if Jan 1 = 1)
    	_		to ignore a column

    Example: If an event consists of platform, date, and number in the form
    		AB20010506.01
    	 a date could be extracted with the format
    		__yyyymmdd___

    Short fields may be right justified; eg, a time field of "20", interpreted
       with a format hhmm, evaluates to 20 min after midnight.
    day of year may not be specified with either month or day of month

output

Time splitter output is an object with added variables. The possible added variables are year, month, day, time, yrday and yrday0. Which variables are added depend on which time fields are described in the input format. The added variables appear on same object level as the input variable being split

If any added variable name already exists in the object, a suffix of the form _N is appended, where N starts from 0 and increases by one. For example, if year, month, and day are to be added to an object that already has a variable called year, the added variables are named year_0, month_0 and day_0. If any of those exist, the added variables are named year_1, month_1, day_1, etc. The same suffix is appended to all variable names added during a single pass through the time splitter.

Last modified: Oct 24, 2008