Editing PHP and MySQL syntax (section)

==== '''human readable''' time format ====
Convert '''unix timestamp''' (the number of seconds since 1970/01/01) <--> to the '''human readable''' time format ex: {{Template:Today}} {{CURRENTTIME}}:06
* php: {{kbd | key=<nowiki>echo date('Y-m-d H:i:s');</nowiki>}} or {{kbd | key=<nowiki>echo date('Y-m-d H:i:s', time() );</nowiki>}} //Convert the time stamp of current time to the human readable time format. Ex: return '{{Template:Today}} {{CURRENTTIME}}:06' {{exclaim}} server timezone dependent
* mysql: {{exclaim}} default client timezone is server timezone<ref>[https://dev.mysql.com/doc/refman/5.5/en/time-zone-support.html MySQL :: MySQL 5.5 Reference Manual :: 10.6 MySQL Server Time Zone Support]</ref>
** {{kbd | key=<nowiki>SELECT NOW();</nowiki>}} Returns {{Template:Today}} {{CURRENTTIME}}:06 which mapping to {{kbd | key=<nowiki>DATETIME</nowiki>}} type<ref>[http://dev.mysql.com/doc/refman/5.1/en/datetime.html MySQL :: MySQL 5.1 Reference Manual :: 11.3.1 The DATE, DATETIME, and TIMESTAMP Types]</ref>
** {{kbd | key=<nowiki>SELECT NOW()+0;</nowiki>}} //2011-04-01 12:19:43 returns 20110401122023.000000
** {{kbd | key=<nowiki>SELECT CURRENT_TIMESTAMP;</nowiki>}} Returns {{Template:Today}} {{CURRENTTIME}}:06 {{exclaim}} [http://stackoverflow.com/questions/2934258/how-do-i-get-the-current-time-zone-of-mysql Current time zone of MySQL] is {{kbd | key=SYSTEM}} & client timezone dependent.
** convert mysql datatype {{kbd | key=timestamp}} (UTC) to Taipei datetime (client timezone dependent) <ref>[http://stackoverflow.com/questions/2934258/how-do-i-get-the-current-time-zone-of-mysql timezone - How do I get the current time zone of MySQL? - Stack Overflow]</ref> 
<pre>
/* approach 1: */
SET time_zone='+8:00';
SELECT CURRENT_TIMESTAMP();

/* approach 2: Detect server timezone automatically! Note the precision of time difference between server timezone to your preferred timezone is hours NOT to minutes */
SELECT convert_tz(
   CURRENT_TIMESTAMP(),   
   CONCAT(
     ROUND(
      TIME_TO_SEC(timediff(now(),convert_tz(now(),@@session.time_zone,'+00:00')))/3600),  ':00')
   , '+08:00');

/* approach 3: If you already know the server timezone ex: -05:00 */
SELECT convert_tz(CURRENT_TIMESTAMP,  '-05:00', '+08:00');
</pre>

* BASH (UNIX shell script) with GUN {{kbd | key=<nowiki>date</nowiki>}} installed in {{Linux}}, {{Mac}} or [https://www.cygwin.com/ Cygwin] of {{Win}}: 
** {{kbd | key=<nowiki>echo $(date '+%Y-%m-%d %H:%M:%S')</nowiki>}}<ref>[https://ss64.com/bash/date.html date Man Page - Linux - SS64.com]</ref> or {{kbd | key=<nowiki>echo `date +\%Y-\%m-\%d\ %H:%M:%S` 2>&1</nowiki>}} or  {{kbd | key=<nowiki>date +\%Y-\%m-\%d\ %H:%M:%S</nowiki>}} Returns {{Template:Today}} {{CURRENTTIME}}:06 {{exclaim}} server timezone dependent
** {{kbd | key=<nowiki>date=`date -I`;echo $date;</nowiki>}} returns {{Template:Today}} on {{Linux}} But it was not supported on Mac 
 and it showed the error message "illegal option -- I" {{exclaim}}