Editing PHP and MySQL syntax (section)

==== Convert human-readable time to '''timestamp''' (string to timestamp) ====
* PHP: Using [http://php.net/manual/en/function.strtotime.php strtotime()] function ex: strtotime('2010-12-21 10:05:06') <ref>[http://stackoverflow.com/questions/113829/how-to-convert-date-to-timestamp-in-php How to convert date to timestamp in PHP? - Stack Overflow]</ref>
* mysql: Using [https://dev.mysql.com/doc/refman/8.0/en/date-and-time-functions.html#function_unix-timestamp UNIX_TIMESTAMP()] function
** {{kbd | key = SELECT UNIX_TIMESTAMP('2011-03-15 18:53:57');}} /* return timestamp: 1300186437 */ {{exclaim}} server timezone dependent
** {{kbd | key = SELECT UNIX_TIMESTAMP(STR_TO_DATE('2011-03-15 18:53:57', '%Y-%m-%d %H:%i:%S'));}} /* return timestamp: 1300186437 */ {{exclaim}} server timezone dependent
* Excel: 
** input data (A2 cell): YYYY/MM/DD (e.g. {{CURRENTYEAR}}/{{CURRENTMONTH}}/{{CURRENTDAY2}} ) or YYYY/MM/DD HH:MM (e.g. {{CURRENTYEAR}}/{{CURRENTMONTH}}/{{CURRENTDAY2}} {{CURRENTTIME}})
** {{kbd | key==(A2-DATE(1970,1,1))*86400}} <ref>[http://stackoverflow.com/questions/1703505/excel-date-to-unix-timestamp Excel date to Unix timestamp - Stack Overflow]</ref>

convert [https://support.office.com/zh-tw/article/DATEVALUE-%E5%87%BD%E6%95%B8-df8b07d4-7761-4a93-bc33-b7471bbff252 datevalue] (number of days since 1900/1/1) ↔ to human-readable date
* Excel: {{kbd | key==DATEVALUE(''Cell_of_date'')}} // ex: {{kbd | key==DATEVALUE("2015/1/27")}} returns 42031. DATEVALUE of 1900/1/1 is 1
* Excel: {{kbd | key==TEXT(''Cell_of_datevalue'',"yyyy/mm/dd")}} // ex: {{kbd | key ==TEXT(42031,"yyyy/mm/dd")}} returns 2015/1/27

convert month name to numeric date ex: {{CURRENTMONTHNAME}} {{CURRENTDAY}}, {{CURRENTYEAR}} -> {{CURRENTYEAR}}-{{CURRENTMONTH}}-{{CURRENTDAY}}
* PHP: 
* MySQL: [http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html#function_str-to-date STR_TO_DATE(str,format)] ex: {{kbd | key=SELECT STR_TO_DATE('{{CURRENTMONTHNAME}} {{CURRENTDAY}}, {{CURRENTYEAR}}', '%M %d, %Y');}} // Returns {{Template:Today}} <ref>[http://stackoverflow.com/questions/7027129/mysql-monthname-from-numbers MySQL MONTHNAME() from numbers - Stack Overflow]</ref>
* Excel