Php > Date Time sample source codes

For all of us who live in places that change between daylight-savings

For all of us who live in places that change between daylight-savings
and standard time. Returns 1 if given time is in daylight savings 0 otherwise 

<?php 

# IS_DAYLIGHT_TIME: Returns 1 (true) if given $time is in daylight savings 
# time; 0 (false) otherwise. 
# 
# Parameters: 
#  (int)$time This is the desired time, in Unix seconds-since-the-epoch 
#       format. 
# 
# Notes: 
# Daylight time is defined as starting at 2am on the first Sunday in April 
# (2am becomes 3am), and ending at 2am on the last Sunday in October (2am 
# becomes 1am). 
# 


function is_daylight_time($time) { 

list($dom, $dow, $month, $hour, $min) = explode( ":", date( "d:w:m:H:i", $time)); 

if   ($month > 4 && $month < 10) { 
  $retval = 1;        # May thru September 
} elseif ($month == 4 && $dom > 7) { 
  $retval = 1;        # After first week in April 
} elseif ($month == 4 && $dom <= 7 && $dow == 0 && $hour >= 2) { 
  $retval = 1;        # After 2am on first Sunday ($dow=0) in April 
} elseif ($month == 4 && $dom <= 7 && $dow != 0 && ($dom-$dow > 0)) { 
  $retval = 1;        # After Sunday of first week in April 
} elseif ($month == 10 && $dom < 25) { 
  $retval = 1;        # Before last week of October 
} elseif ($month == 10 && $dom >= 25 && $dow == 0 && $hour < 2) { 
  $retval = 1;        # Before 2am on last Sunday in October 
} elseif ($month == 10 && $dom >= 25 && $dow != 0 && ($dom-24-$dow < 1) ) { 
  $retval = 1;        # Before Sunday of last week in October 
} else { 
  $retval = 0; 
} 

return($retval); 

?>