check Date format : Regular Expressions « Development « JavaScript DHTML

1. JavaScript DHTML
2. Development
3. Regular Expressions

check Date format

   
<!-- 
     Example File From "JavaScript and DHTML Cookbook"
     Published by O'Reilly & Associates
     Copyright 2003 Danny Goodman
-->

function checkDate(fld) {
    var mo, day, yr;
    var entry = fld.value;
    var re = /\b\d{1,2}[\/-]\d{1,2}[\/-]\d{4}\b/;
    if (re.test(entry)) {
        var delimChar = (entry.indexOf("/") != -1) ? "/" : "-";
        var delim1 = entry.indexOf(delimChar);
        var delim2 = entry.lastIndexOf(delimChar);
        mo = parseInt(entry.substring(0, delim1), 10);
        day = parseInt(entry.substring(delim1+1, delim2), 10);
        yr = parseInt(entry.substring(delim2+1), 10);
        var testDate = new Date(yr, mo-1, day);
        alert(testDate)
        if (testDate.getDate() == day) {
            if (testDate.getMonth() + 1 == mo) {
                if (testDate.getFullYear() == yr) {
                    return true;
                } else {
                    alert("There is a problem with the year entry.");
                }
            } else {
                alert("There is a problem with the month entry.");
            }
        } else {
            alert("There is a problem with the date entry.");
        }
    } else {
        alert("Incorrect date format. Enter as mm/dd/yyyy.");
    }
    return false;
}

function validateDate(fld) {
    if (!checkDate(fld)) {
        // focus if validation fails
        fld.focus();
        fld.select();
    }
}

----------

function checkDate(fld) {
    var mo, day, yr;
    var entry = fld.value;
    var reLong = /\b\d{1,2}[\/-]\d{1,2}[\/-]\d{4}\b/;
    var reShort = /\b\d{1,2}[\/-]\d{1,2}[\/-]\d{2}\b/;
    var valid = (reLong.test(entry)) || (reShort.test(entry));
    if (valid) {
        var delimChar = (entry.indexOf("/") != -1) ? "/" : "-";
        var delim1 = entry.indexOf(delimChar);
        var delim2 = entry.lastIndexOf(delimChar);
        mo = parseInt(entry.substring(0, delim1), 10);
        day = parseInt(entry.substring(delim1+1, delim2), 10);
        yr = parseInt(entry.substring(delim2+1), 10);
        // handle two-digit year
        if (yr < 100) {
            var today = new Date();
            // get current century floor (e.g., 2000)
            var currCent = parseInt(today.getFullYear() / 100) * 100;
            // two digits up to this year + 15 expands to current century
            var threshold = (today.getFullYear() + 15) - currCent;
            if (yr > threshold) {
                yr += currCent - 100;
            } else {
                yr += currCent;
            }
        }
        var testDate = new Date(yr, mo-1, day);
        if (testDate.getDate() == day) {
            if (testDate.getMonth() + 1 == mo) {
                if (testDate.getFullYear() == yr) {
                    // fill field with database-friendly format
                    fld.value = mo + "/" + day + "/" + yr;
                    return true;
                } else {
                    alert("There is a problem with the year entry.");
                }
            } else {
                alert("There is a problem with the month entry.");
            }
        } else {
            alert("There is a problem with the date entry.");
        }
    } else {
        alert("Incorrect date format. Enter as mm/dd/yyyy.");
    }
    return false;
}


           
         
    
    
  

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