- printf: documentation ( source)
<?php
function diff($a, $b) {
static $FMT = "Y-m-d H:i:s P (\D\S\T=I)";
printf("%20s: %s -> %s\n", $a->format("e"), $a->format($FMT), $b->format($FMT));
}
$havana1 = new DateTime("@1615611600");
$havana1->setTimezone(new DateTimeZone("America/Havana"));
$havana2 = (clone $havana1)->add(new DateInterval("P1D"));
diff($havana1, $havana2);
$tehran1 = new DateTime("@1616272200");
$tehran1->setTimezone(new DateTimeZone("Asia/Tehran"));
$tehran2 = (clone $tehran1)->add(new DateInterval("P1D"));
diff($tehran1, $tehran2);