PHP Calendar Functions Complete Reference Last Updated : 12 Jul, 2025 Comments Improve Suggest changes 4 Likes Like Report The calendar extension contains a series of functions to represent the calendar date into a different format. The standard date is based on Julian Day Count. The date count starting from January 1st, 4713 B.C. is known as Julian Day Count. First, the date is converted into Julian Day Count and then converted into a calendar system. Example: The program below illustrate the use of jdtofrench() function. PHP <?php // PHP program to demonstrate the // use of jdtofrench() function // converts date to julian integer $jd = frenchtojd(1, 7, 13); // prints the julian day integer echo "The julian day integer is ", $jd, "\n"; // converts the Julian day to French date $date = jdtofrench($jd); // prints the date echo "The french date initially taken was ", ($date), "\n"; ?> Output: The julian day integer is 2380229 The french date initially taken was 1/7/13 The complete list of calendar functions are given below: PHP Calendar FunctionsDescriptioncal_days_in_month()Return the number of days in a month for a specific year. cal_from_jd()Returns the array containing calendar information of the specified calendar.cal_info()Return information about a specified calendar. cal_to_jd()Convert a specified date into Julian Day Count. easter_date()Returns the Easter date in the year passed as an argument. easter_days()Returns the number of days after March 21, that the Easter Day is in the given yearfrenchtojd()Convert the date in the French republican calendar and converts it to a Julian Day count.gregoriantojd()Converts a Gregorian date to a Julian Day Count. jddayofweek()Returns the given day of the week of a Julian integer passed in the argument.jdmonthname()Returns the month name of a Julian day number passed as the argument. jdtofrench()Converts a Julian Day Integer to a French date. jdtogregorian()Converts a Julian Day Integer to a Gregorian date.jdtojulian()Convert a Julian day count to a Julian calendar date.jdtounix()Convert a Julian day date into a Unix Timestamp. jewishtojd()Converts a Jewish Date to a Julian Day Count.juliantojd()Convert Julian calendar Date to Julian Day countunixtojd()Converts the Unix timestamp to Julian Day count. Comment D dharmendra_kumar Follow 4 Improve D dharmendra_kumar Follow 4 Improve Article Tags : Web Technologies PHP PHP-date-time Explore PHP Tutorial 8 min read BasicsPHP Syntax 4 min read PHP Variables 5 min read PHP | Functions 8 min read PHP Loops 4 min read ArrayPHP Arrays 5 min read PHP Associative Arrays 4 min read Multidimensional arrays in PHP 5 min read Sorting Arrays in PHP 4 min read OOPs & InterfacesPHP Classes 2 min read PHP | Constructors and Destructors 5 min read PHP Access Modifiers 4 min read Multiple Inheritance in PHP 4 min read MySQL DatabasePHP | MySQL Database Introduction 4 min read PHP Database connection 2 min read PHP | MySQL ( Creating Database ) 3 min read PHP | MySQL ( Creating Table ) 3 min read PHP AdvancePHP Superglobals 6 min read PHP | Regular Expressions 12 min read PHP Form Handling 4 min read PHP File Handling 4 min read PHP | Uploading File 3 min read PHP Cookies 9 min read PHP | Sessions 7 min read Like