CFLib.org – Common Function Library Project

Description:
Offsets a date according to a passed-in mask. The mask is of format: [value][datepart] eg: 1d (one day) The value must be an integer, and the datePart must be one of "y" for years, "m" for months, "w" for weeks, "d" for days, "h" for hours, "n" for minutes and "s" for seconds. Multiple mask items can be specified, eg: 1d2h3s is one day, two hours and three seconds.

Return Values:
Returns a date offset as per the mask

Example:

// SAMPLES

offsetDate("1d"); // == dateAdd("d", 1, now())
offsetDate("1y", "2013-01-01") // == "2014-01-01"
offsetDate("1m1d") // == Add 1 month and 1 day to now()
offsetDate("-43Y0M+10D") // == subtracts 43 years, adds zero months and ten days to now()


// TESTS

function assert(val1, val2) { if( !dateCompare(val1, val2) == 0 ) throw('"#val1#" != "#val2#"'); }

assert(offsetDate("1y", "2013-01-01"), "2014-01-01");
assert(offsetDate("1m", "2013-01-01"), "2013-02-01");
assert(offsetDate("1w", "2013-01-01"), "2013-01-08");
assert(offsetDate("1d", "2013-01-01"), "2013-01-02");
assert(offsetDate("1h", "2013-01-01 00:00:00"), "2013-01-01 01:00:00");
assert(offsetDate("1n", "2013-01-01 00:00:00"), "2013-01-01 00:01:00");
assert(offsetDate("1s", "2013-01-01 00:00:00"), "2013-01-01 00:00:01");
assert(offsetDate("1y1d1n", "2013-01-01 00:00:00"), "2014-01-02 00:01:00");

Parameters:

Full UDF Source:

/**
 * Offset a date according to a datepart defined by a mask.
 * v0.9 by Loïc Mahieu
 * v1.0 by Adam Cameron (improved regex, removed redundant code, renamed function to be less vague)
 * 
 * @param offset      A string containing a date mask (as per description) (Required)
 * @param refDate      A date. Defaults to now() (Optional)
 * @return Returns a date offset as per the mask 
 * @author Loïc Mahieu (loic@igloo.be) 
 * @version 1.0, February 7, 2013 
 */
function offsetDate(required string offset, date refDate = now()) {
    var matcher = createObject("java", "java.util.regex.Pattern")
        .compile("(?i)([+-]?[0-9]+)\s*([snhdwmy])")
        .matcher(offset);

    while (matcher.find()) {
        var match = matcher.group(1);
        var datePart = matcher.group(2);

        if (datePart == "y"){
            datePart = "yyyy";
        }
        else if (datePart == "w"){
            datePart = "ww";
        }
        refDate = dateAdd(datePart, match, refDate);
    }
    return refDate;
}