diff --git a/php/src/php/time/Hour.php b/php/src/php/time/Hour.php
new file mode 100644
index 0000000..72be43e
--- /dev/null
+++ b/php/src/php/time/Hour.php
@@ -0,0 +1,16 @@
+<?php
+namespace nulib\php\time;
+
+class Hour extends Time {
+  const UNIT = self::UNIT_MINUTES;
+
+  const FORMAT = "%hh%M";
+
+  function format(?string $format=null): string {
+    $string = parent::format($format);
+    if (substr($string, -3) == "h00") {
+      $string = substr($string, 0, -2);
+    }
+    return $string;
+  }
+}
diff --git a/php/src/php/time/Time.php b/php/src/php/time/Time.php
new file mode 100644
index 0000000..a0d5591
--- /dev/null
+++ b/php/src/php/time/Time.php
@@ -0,0 +1,288 @@
+<?php
+namespace nulib\php\time;
+
+use DateTimeInterface;
+use nulib\exceptions;
+use nulib\php\types\vbool;
+use nulib\php\types\vint;
+
+/**
+ * Class Time: une heure allant de 0h à 24h inclus.
+ *
+ * la seule utilisation autorisée de "24h" est comme borne supérieure pour une
+ * plage horaire.
+ */
+class Time {
+  const UNIT_HOURS = 3600;
+  const UNIT_MINUTES = 60;
+  const UNIT_SECONDS = 1;
+
+  const PATTERNS = [
+    '/^(\d+)[:.h](\d+)(?:[:.](\d+))?$/',
+    '/^(\d+)h(?:(\d+)(?:[:.](\d+))?)?$/'
+  ];
+
+  /** @var string format par défaut pour l'affichage */
+  const FORMAT = "%H:%M:%S";
+
+  static function with($time): self {
+    if ($time instanceof static) return $time;
+    else return new static($time);
+  }
+
+  static function withn($time): ?self {
+    if ($time === null) return null;
+    elseif ($time instanceof static) return $time;
+    else return new static($time);
+  }
+
+  static function isa_time($time): bool {
+    if ($time === null) return false;
+    if ($time instanceof self) return true;
+    if (is_int($time)) return true;
+    if (is_string($time)) {
+      foreach (self::PATTERNS as $pattern) {
+        if (preg_match($pattern, $time)) return true;
+      }
+    }
+    if ($time instanceof DateTimeInterface) return true;
+    if (is_array($time) && count($time) == 3) return true;
+    return false;
+  }
+
+  protected static function s_now(): int {
+    $hms = date('His');
+    return intval(substr($hms, 0, 2)) * 3600
+      + intval(substr($hms, 2, 2)) * 60
+      + intval(substr($hms, 4, 2));
+  }
+
+  protected static function s_get($time, int $unit=self::UNIT_SECONDS): int {
+    if ($time === null) {
+      return 0;
+    } elseif ($time instanceof self) {
+      return $time->getSeconds();
+    } elseif (is_int($time)) {
+      return $time * $unit;
+    } elseif (is_string($time)) {
+      $matched = false;
+      foreach (self::PATTERNS as $pattern) {
+        if (preg_match($pattern, $time, $ms)) {
+          $matched = true;
+          break;
+        }
+      }
+      if ($matched) {
+        $h = $ms[1];
+        $m = $ms[2] ?? 0;
+        $s = $ms[3] ?? 0;
+        return intval($h) * 3600 + intval($m) * 60 + intval($s);
+      }
+    } elseif ($time instanceof DateTimeInterface) {
+      $hms = $time->format('His');
+      return intval(substr($hms, 0, 2)) * 3600
+        + intval(substr($hms, 2, 2)) * 60
+        + intval(substr($hms, 4, 2));
+    } elseif (is_array($time) && count($time) == 3) {
+      [$h, $m, $s] = $time;
+      return $h * 3600 + $m * 60 + $s;
+    }
+    throw exceptions::invalid_value($time, "time");
+  }
+
+  protected static function s_adjust(int &$seconds, int $unit=self::UNIT_SECONDS, ?int $step=null): int {
+    if ($step !== null) $unit *= $step;
+    $adjust = $seconds % $unit;
+    if ($seconds < 0) $adjust = -$adjust;
+    $seconds -= $adjust;
+    return $seconds;
+  }
+
+  protected static function s_wrap_start(int &$seconds): int {
+    while ($seconds < 0) $seconds += 86400;
+    if ($seconds >= 86400) $seconds %= 86400;
+    return $seconds;
+  }
+
+  protected static function s_wrap_end(int &$seconds): int {
+    while ($seconds < 0) $seconds += 86400;
+    if ($seconds > 86400) $seconds %= 86400;
+    return $seconds;
+  }
+
+  /**
+   * @var int la valeur de l'unité en secondes, pour le constructeur et les
+   * méthodes {@link setu()}, {@link addu()} et {@link subu()}
+   */
+  const UNIT = self::UNIT_SECONDS;
+
+  /**
+   * @var int|null un nombre d'unité dont l'heure doit être multiple. par
+   * exemple, si l'unité est la minute, une valeur 5 permet d'avoir des heures
+   * qui vont de 5 en 5 minutes (0h00, 0h05, 0h10, etc.)
+   */
+  const STEP = null;
+
+  /** @var bool s'il faut garder les heures dans la plage [0, 24h] */
+  const WRAP = true;
+
+  function __construct($time=null, ?array $params=null) {
+    $this->unit = vint::with($params["unit"] ?? static::UNIT);
+    $this->step = vint::withn($params["step"] ?? self::STEP);
+    $this->wrap = vbool::with($params["wrap"] ?? self::WRAP);
+    if ($time === null) $seconds = self::s_now();
+    else $seconds = self::s_get($time, $this->unit);
+    $this->setSeconds($seconds);
+  }
+
+  protected int $unit;
+
+  protected ?int $step;
+
+  protected bool $wrap;
+
+  protected int $seconds;
+
+  function getSeconds(): int {
+    return $this->seconds;
+  }
+
+  /**
+   * mettre à jour cet objet avec le nombre de secondes spécifié
+   *
+   * le nombre effectif de secondes est calculé en tenant compte de l'unité
+   * actuelle
+   *
+   * @return int le nombre de seconde effectif, après correction
+   */
+  protected function setSeconds(?int $seconds): int {
+    $this->seconds = $seconds ?? self::s_now();
+    return $this->afterUpdate();
+  }
+
+  protected function afterUpdate(): int {
+    self::s_adjust($this->seconds, $this->unit, $this->step);
+    if ($this->wrap) $this->wrapEnd();
+    return $this->seconds;
+  }
+
+  /**
+   * wrapper l'heure pour la garder dans la plage [0h, 24h[ ce qui la rend
+   * propice à l'utilisation comme borne inférieure d'une période
+   */
+  function wrapStart(): self {
+    self::s_wrap_start($this->seconds);
+    return $this;
+  }
+
+  /**
+   * wrapper l'heure pour la garder dans la plage [0h, 24h] ce qui la rend
+   * propice à l'utilisation comme borne supérieure d'une période
+   */
+  function wrapEnd(): self {
+    self::s_wrap_end($this->seconds);
+    return $this;
+  }
+
+  /** formatter cette heure pour affichage */
+  function format(?string $format=null): string {
+    if ($format === null) $format = static::FORMAT;
+    $v = $this->seconds;
+    $h = intdiv($v, 3600); $v = $v % 3600;
+    $m = intdiv($v, 60);
+    $s = $v % 60;
+    $searches = [
+      "%H", "%h",
+      "%M", "%m",
+      "%S", "%s",
+      "%%",
+    ];
+    $replaces = [
+      sprintf("%02u", $h), strval($h),
+      sprintf("%02u", $m), strval($m),
+      sprintf("%02u", $s), strval($s),
+      "%",
+    ];
+    return str_replace($searches, $replaces, $format);
+  }
+
+  function __toString(): string {
+    return $this->format();
+  }
+
+  /** @return int le nombre d'unités */
+  function getu(): int {
+    return intdiv($this->seconds, $this->unit);
+  }
+
+  /** créer une nouvelle heure avec le nombre d'unités spécifiées */
+  function setu(int $count): self {
+    $this->setSeconds($count * $this->unit);
+    return $this;
+  }
+
+  /** créer une nouvelle heure en ajoutant à cette heure le nombre d'unités spécifiées */
+  function addu(int $count=1): self {
+    $count *= $this->unit;
+    if ($this->step !== null) $count *= $this->step;
+    $this->setSeconds($this->seconds + $count);
+    return $this;
+  }
+
+  /** créer une nouvelle heure en soustrayant à cette heure le nombre d'unités spécifiées */
+  function subu(int $count=1): self {
+    $count *= $this->unit;
+    if ($this->step !== null) $count *= $this->step;
+    $this->setSeconds($this->seconds - $count);
+    return $this;
+  }
+
+  /** forcer cette heure à l'heure spécifiée */
+  function set($time): self {
+    if ($time === null) $seconds = self::s_now();
+    else $seconds = self::with($time)->getSeconds();
+    $this->setSeconds($seconds);
+    return $this;
+  }
+
+  /** ajouter à cette heure l'heure spécifiée */
+  function add($time): self {
+    if ($time !== null) {
+      $this->setSeconds($this->seconds + self::with($time)->getSeconds());
+    }
+    return $this;
+  }
+
+  /** soustraire à cette heure l'heure spécifiée */
+  function sub($time): self {
+    if ($time !== null) {
+      $this->setSeconds($this->seconds - self::with($time)->getSeconds());
+    }
+    return $this;
+  }
+
+  /**
+   * comparer avec l'heure spécifiée. retourner une valeur négative, égale à
+   * zéro ou positive suivant le résultat de la comparaison
+   */
+  function compare($time): int {
+    if ($time === null) return 1;
+    else return $this->seconds - self::with($time)->getSeconds();
+  }
+
+  /**
+   * tester si cette heure est avant ou égale à l'heure spécifiée
+   */
+  function before($other): bool {
+    if ($other === null) return false;
+    else return $this->seconds <= self::with($other)->getSeconds();
+  }
+
+  /**
+   * tester si cette heure est après ou égale à l'heure spécifiée
+   */
+  function after($other): bool {
+    if ($other === null) return true;
+    else return $this->seconds >= self::with($other)->getSeconds();
+  }
+}
diff --git a/php/src/php/types/vdate.php b/php/src/php/types/vdate.php
new file mode 100644
index 0000000..3f102f7
--- /dev/null
+++ b/php/src/php/types/vdate.php
@@ -0,0 +1,29 @@
+<?php
+namespace nulib\php\types;
+
+use nulib\php\time\Date;
+
+class vdate {
+  static function isa($value, bool $strict=false) : bool {
+    if ($strict) return $value instanceof Date;
+    else return Date::isa_date($value);
+  }
+
+  static function ensure(&$date): void {
+    $date = Date::with($date);
+  }
+
+  static function ensuren(&$date): void {
+    $date = Date::withn($date);
+  }
+
+  static function with($value): Date {
+    self::ensure($value);
+    return $value;
+  }
+
+  static function withn($value): ?Date {
+    self::ensuren($value);
+    return $value;
+  }
+}
diff --git a/php/src/php/types/vdatetime.php b/php/src/php/types/vdatetime.php
new file mode 100644
index 0000000..7304438
--- /dev/null
+++ b/php/src/php/types/vdatetime.php
@@ -0,0 +1,29 @@
+<?php
+namespace nulib\php\types;
+
+use nulib\php\time\DateTime;
+
+class vdatetime {
+  static function isa($value, bool $strict=false) : bool {
+    if ($strict) return $value instanceof DateTime;
+    else return DateTime::isa_datetime($value);
+  }
+
+  static function ensure(&$datetime): void {
+    $datetime = DateTime::with($datetime);
+  }
+
+  static function ensuren(&$datetime): void {
+    $datetime = DateTime::withn($datetime);
+  }
+
+  static function with($value): DateTime {
+    self::ensure($value);
+    return $value;
+  }
+
+  static function withn($value): ?DateTime {
+    self::ensuren($value);
+    return $value;
+  }
+}
diff --git a/php/src/php/types/vmixed.php b/php/src/php/types/vmixed.php
new file mode 100644
index 0000000..ec02597
--- /dev/null
+++ b/php/src/php/types/vmixed.php
@@ -0,0 +1,22 @@
+<?php
+namespace nulib\php\types;
+
+class vmixed {
+  static function isa($value, bool $strict=false) : bool {
+    return true;
+  }
+
+  static function ensure(&$mixed): void {
+  }
+
+  static function ensuren(&$mixed): void {
+  }
+
+  static function with($value) {
+    return $value;
+  }
+
+  static function withn($value) {
+    return $value;
+  }
+}
diff --git a/php/src/php/types/vraw.php b/php/src/php/types/vraw.php
new file mode 100644
index 0000000..ef3ee0a
--- /dev/null
+++ b/php/src/php/types/vraw.php
@@ -0,0 +1,22 @@
+<?php
+namespace nulib\php\types;
+
+class vraw {
+  static function isa($value, bool $strict=false) : bool {
+    return true;
+  }
+
+  static function ensure(&$raw): void {
+  }
+
+  static function ensuren(&$raw): void {
+  }
+
+  static function with($value) {
+    return $value;
+  }
+
+  static function withn($value) {
+    return $value;
+  }
+}
diff --git a/php/src/php/types/vtime.php b/php/src/php/types/vtime.php
new file mode 100644
index 0000000..a96dbe8
--- /dev/null
+++ b/php/src/php/types/vtime.php
@@ -0,0 +1,30 @@
+<?php
+namespace nulib\php\types;
+
+use nulib\php\time\DateTime;
+use nulib\php\time\Time;
+
+class vtime {
+  static function isa($value, bool $strict=false) : bool {
+    if ($strict) return $value instanceof Time;
+    else return Time::isa_time($value);
+  }
+
+  static function ensure(&$time): void {
+    $time = Time::with($time);
+  }
+
+  static function ensuren(&$time): void {
+    $time = Time::withn($time);
+  }
+
+  static function with($value): Time {
+    self::ensure($value);
+    return $value;
+  }
+
+  static function withn($value): ?Time {
+    self::ensuren($value);
+    return $value;
+  }
+}
diff --git a/php/tests/php/time/HourTest.php b/php/tests/php/time/HourTest.php
new file mode 100644
index 0000000..1cb35b4
--- /dev/null
+++ b/php/tests/php/time/HourTest.php
@@ -0,0 +1,60 @@
+<?php
+namespace nulib\php\time;
+
+use nulib\tests\TestCase;
+use nulib\ValueException;
+
+class HourTest extends TestCase {
+  function testParse() {
+    self::assertSame("8h", strval(new Hour("08:00:00")));
+    self::assertSame("8h", strval(new Hour("8:0")));
+    self::assertSame("8h", strval(new Hour("8.0")));
+    self::assertSame("8h", strval(new Hour("8h")));
+
+    self::assertSame("8h15", strval(new Hour("08:15:00")));
+    self::assertSame("8h15", strval(new Hour("8:15")));
+    self::assertSame("8h15", strval(new Hour("8.15")));
+    self::assertSame("8h15", strval(new Hour("8h15")));
+
+    self::assertSame("8h15", strval(new Hour("08:15:23")));
+    self::assertSame("8h15", strval(new Hour("8:15.23")));
+    self::assertSame("8h15", strval(new Hour("8.15.23")));
+    self::assertSame("8h15", strval(new Hour("8h15.23")));
+
+    self::assertSame("31h11", strval(new Hour("30:70:80", [
+      "wrap" => false,
+    ])));
+    self::assertSame("7h11", strval(new Hour("30:70:80")));
+
+    self::assertException(ValueException::class, function() {
+      return strval(new Hour("bad format"));
+    });
+  }
+
+  function testFormat() {
+    self::assertSame("0h", (new Hour(0))->format());
+    self::assertSame("0h56", (new Hour(56))->format());
+    self::assertSame("2h", (new Hour(120))->format());
+    self::assertSame("23h59", (new Hour(1439))->format());
+    self::assertSame("24h", (new Hour(1440))->format());
+    self::assertSame("0h01", (new Hour(1441))->format());
+  }
+
+  function testStep() {
+    $h = new Hour(null, [
+      "step" => 5,
+    ]);
+    $h->setu(10); self::assertSame("0h10", strval($h));
+    $h->setu(12); self::assertSame("0h10", strval($h));
+    $h->setu(15); self::assertSame("0h15", strval($h));
+    $h->setu(17); self::assertSame("0h15", strval($h));
+
+    $h->set("8h");
+    $h->addu(); self::assertSame("8h05", strval($h));
+    $h->addu(); self::assertSame("8h10", strval($h));
+    $h->addu(); self::assertSame("8h15", strval($h));
+    $h->subu(); self::assertSame("8h10", strval($h));
+    $h->subu(); self::assertSame("8h05", strval($h));
+    $h->subu(); self::assertSame("8h", strval($h));
+  }
+}
diff --git a/php/tests/php/time/TimeTest.php b/php/tests/php/time/TimeTest.php
new file mode 100644
index 0000000..998b0cb
--- /dev/null
+++ b/php/tests/php/time/TimeTest.php
@@ -0,0 +1,74 @@
+<?php
+namespace nulib\php\time;
+
+use nulib\tests\TestCase;
+use nulib\ValueException;
+
+class TimeTest extends TestCase {
+  function testParse() {
+    self::assertSame("08:00:00", strval(new Time("08:00:00")));
+    self::assertSame("08:00:00", strval(new Time("8:0")));
+    self::assertSame("08:00:00", strval(new Time("8.0")));
+    self::assertSame("08:00:00", strval(new Time("8h")));
+
+    self::assertSame("08:15:00", strval(new Time("08:15:00")));
+    self::assertSame("08:15:00", strval(new Time("8:15")));
+    self::assertSame("08:15:00", strval(new Time("8.15")));
+    self::assertSame("08:15:00", strval(new Time("8h15")));
+
+    self::assertSame("08:15:23", strval(new Time("08:15:23")));
+    self::assertSame("08:15:23", strval(new Time("8:15.23")));
+    self::assertSame("08:15:23", strval(new Time("8.15.23")));
+    self::assertSame("08:15:23", strval(new Time("8h15.23")));
+
+    self::assertSame("31:11:20", strval(new Time("30:70:80", [
+      "wrap" => false,
+    ])));
+    self::assertSame("07:11:20", strval(new Time("30:70:80")));
+
+    self::assertException(ValueException::class, function() {
+      return strval(new Time("bad format"));
+    });
+  }
+
+  function testGetu() {
+    self::assertSame(0, (new Time(0))->getu());
+    self::assertSame(86399, (new Time(-1))->getu());
+    self::assertSame(1, (new Time(1))->getu());
+    self::assertSame(120, (new Time(120))->getu());
+    self::assertSame(86400, (new Time(86400))->getu());
+    self::assertSame(0, (new Time(-86400))->getu());
+  }
+
+  function testAddu() {
+    $t = new Time(0);
+    $t->addu(0); self::assertSame(0, $t->getu());
+    $t->addu(10); self::assertSame(10, $t->getu());
+    $t->addu(10); self::assertSame(20, $t->getu());
+    $t->addu(100); self::assertSame(120, $t->getu());
+    $t->addu(86280); self::assertSame(86400, $t->getu());
+    $t->addu(86400); self::assertSame(0, $t->getu());
+    $t->addu(-86400); self::assertSame(0, $t->getu());
+  }
+
+  function testSubu() {
+    $t = new Time(0);
+    $t->subu(-86400); self::assertSame(86400, $t->getu());
+    $t->subu(86400); self::assertSame(0, $t->getu());
+    
+    $t = new Time(120);
+    $t->subu(100); self::assertSame(20, $t->getu());
+    $t->subu(10); self::assertSame(10, $t->getu());
+    $t->subu(10); self::assertSame(0, $t->getu());
+    $t->subu(0); self::assertSame(0, $t->getu());
+  }
+
+  function testFormat() {
+    self::assertSame("00:00:00", (new Time(0))->format());
+    self::assertSame("00:00:56", (new Time(56))->format());
+    self::assertSame("00:02:00", (new Time(120))->format());
+    self::assertSame("23:59:59", (new Time(86399))->format());
+    self::assertSame("24:00:00", (new Time(86400))->format());
+    self::assertSame("00:00:01", (new Time(86401))->format());
+  }
+}