+ // Do UTC
+ $structure[] = '<optgroup label="'. esc_attr__( 'UTC' ) .'">';
+ $selected = '';
+ if ( 'UTC' === $selected_zone )
+ $selected = 'selected="selected" ';
+ $structure[] = '<option ' . $selected . 'value="' . esc_attr( 'UTC' ) . '">' . __('UTC') . '</option>';
+ $structure[] = '</optgroup>';
+
+ // Do manual UTC offsets
+ $structure[] = '<optgroup label="'. esc_attr__( 'Manual Offsets' ) .'">';
+ $offset_range = array (-12, -11.5, -11, -10.5, -10, -9.5, -9, -8.5, -8, -7.5, -7, -6.5, -6, -5.5, -5, -4.5, -4, -3.5, -3, -2.5, -2, -1.5, -1, -0.5,
+ 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 5.75, 6, 6.5, 7, 7.5, 8, 8.5, 8.75, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.75, 13, 13.75, 14);
+ foreach ( $offset_range as $offset ) {
+ if ( 0 <= $offset )
+ $offset_name = '+' . $offset;
+ else
+ $offset_name = (string) $offset;
+
+ $offset_value = $offset_name;
+ $offset_name = str_replace(array('.25','.5','.75'), array(':15',':30',':45'), $offset_name);
+ $offset_name = 'UTC' . $offset_name;
+ $offset_value = 'UTC' . $offset_value;
+ $selected = '';
+ if ( $offset_value === $selected_zone )
+ $selected = 'selected="selected" ';
+ $structure[] = '<option ' . $selected . 'value="' . esc_attr( $offset_value ) . '">' . esc_html( $offset_name ) . "</option>";
+
+ }
+ $structure[] = '</optgroup>';
+