diff --git a/src/inc/calendarsView.php b/src/inc/calendarsView.php
index 46a3761..03d1486 100644
--- a/src/inc/calendarsView.php
+++ b/src/inc/calendarsView.php
@@ -33,7 +33,7 @@
 
       if ($dow == 1) echo "</tr>";
       if ($dom == 1) echo "</table>";
-      if ($dom == 1 || $start) echo "<div class='month'>".security::htmlsafe(ucfirst(strftime("%B %G", $current->getTimestamp())))."</div><table class='calendar'>";
+      if ($dom == 1 || $start) echo "<div class='month'>".security::htmlsafe(ucfirst(date::getMonthYear($current->getTimestamp())))."</div><table class='calendar'>";
       if ($dow == 1 || $start) echo "<tr>";
       if ($dom == 1 || $start) {
         for ($i = 1; $i < $dow; $i++) {
diff --git a/src/inc/date.php b/src/inc/date.php
new file mode 100644
index 0000000..ba89c09
--- /dev/null
+++ b/src/inc/date.php
@@ -0,0 +1,35 @@
+<?php
+class date {
+  const LOCALE = 'es';
+
+  private static function createFormatter(string $pattern) {
+    return new IntlDateFormatter(
+        locale: self::LOCALE,
+        dateType: IntlDateFormatter::FULL,
+        timeType: IntlDateFormatter::FULL,
+        timezone: null,
+        calendar: IntlDateFormatter::GREGORIAN,
+        pattern: $pattern
+    );
+  }
+
+  public static function getMonthYear(IntlCalendar|DateTimeInterface|array|string|int|float $timestamp) {
+    static $formatter = self::createFormatter("MMMM yyyy");
+    return $formatter->format($timestamp);
+  }
+
+  public static function getShortDate(IntlCalendar|DateTimeInterface|array|string|int|float $timestamp) {
+    static $formatter = self::createFormatter("dd MMM yyyy");
+    return $formatter->format($timestamp);
+  }
+
+  public static function getShortDateWithTime(IntlCalendar|DateTimeInterface|array|string|int|float $timestamp) {
+    static $formatter = self::createFormatter("dd MMM yyyy HH:mm:ss");
+    return $formatter->format($timestamp);
+  }
+
+  public static function getLongDate(IntlCalendar|DateTimeInterface|array|string|int|float $timestamp) {
+    static $formatter = self::createFormatter("dd 'de' MMMM 'de' yyyy");
+    return $formatter->format($timestamp);
+  }
+}
diff --git a/src/inc/incidents.php b/src/inc/incidents.php
index b558ed9..7bda42d 100644
--- a/src/inc/incidents.php
+++ b/src/inc/incidents.php
@@ -486,13 +486,13 @@
 
       if (!count($to)) return 0;
 
-      $subject = "Incidencia del tipo \"".security::htmlsafe($incidenttype["name"])."\" creada para ".security::htmlsafe($workerName)." el ".strftime("%d %b %Y", $sday);
+      $subject = "Incidencia del tipo \"".security::htmlsafe($incidenttype["name"])."\" creada para ".security::htmlsafe($workerName)." el ".date::getShortDate($sday);
       $body = mail::bodyTemplate("<p>Hola,</p>
       <p>Este es un mensaje automático para avisarte de que ".security::htmlsafe(people::userData("name"))." ha introducido la siguiente incidencia en el sistema de registro horario:</p>
       <ul>
         <li><b>Trabajador:</b> ".security::htmlsafe($workerName)."</li>
         <li><b>Motivo:</b> ".security::htmlsafe($incidenttype["name"])."</li>
-        <li><b>Fecha:</b> ".strftime("%d %b %Y", $sday)." ".(($sbegins == 0 && $sends == self::ENDOFDAY) ? "(todo el día)": schedules::sec2time($sbegins)."-".schedules::sec2time($sends))."</li>".
+        <li><b>Fecha:</b> ".date::getShortDate($sday)." ".(($sbegins == 0 && $sends == self::ENDOFDAY) ? "(todo el día)": schedules::sec2time($sbegins)."-".schedules::sec2time($sends))."</li>".
         (!empty($details) ? "<li><b>Observaciones:</b> <span style='white-space: pre-wrap;'>".security::htmlsafe($details)."</span></li>" : "").
       "</ul>
       <p style='font-size: 11px;'>Has recibido este mensaje porque estás configurado como persona responsable de la categoría a la que pertenece este trabajador o eres el administrador del sistema.</p>");
@@ -568,9 +568,9 @@
           "email" => $workerEmail,
           "name" => $workerName
         )];
-        $subject = "Incidencia del ".strftime("%d %b %Y", $incident["day"])." ".($value == 1 ? "verificada" : "rechazada");
+        $subject = "Incidencia del ".date::getShortDate($incident["day"])." ".($value == 1 ? "verificada" : "rechazada");
         $body = mail::bodyTemplate("<p>Bienvenido ".security::htmlsafe($workerName).",</p>
-        <p>Este es un mensaje automático para avisarte de que la incidencia que introduciste para el día ".strftime("%d de %B de %Y", $incident["day"])." ha sido ".($value == 1 ? "aceptada" : "rechazada").".</p><p>Puedes ver el estado de todas tus incidencias en el <a href='".security::htmlsafe($conf["fullPath"])."'>aplicativo web</a>.</p>");
+        <p>Este es un mensaje automático para avisarte de que la incidencia que introduciste para el día ".date::getLongDate($incident["day"])." ha sido ".($value == 1 ? "aceptada" : "rechazada").".</p><p>Puedes ver el estado de todas tus incidencias en el <a href='".security::htmlsafe($conf["fullPath"])."'>aplicativo web</a>.</p>");
 
         mail::send($to, [], $subject, $body);
       }
diff --git a/src/inc/incidentsView.php b/src/inc/incidentsView.php
index 1f90bc8..5bd0bda 100644
--- a/src/inc/incidentsView.php
+++ b/src/inc/incidentsView.php
@@ -119,7 +119,7 @@
               <?php
             }
             ?>
-            <td class="can-strike"><?=strftime("%d %b %Y", $incident["day"])." ".security::htmlsafe($incident["allday"] ? "(todo el día)" : schedules::sec2time($incident["begins"])."-".schedules::sec2time($incident["ends"]))?></td>
+            <td class="can-strike"><?=date::getShortDate($incident["day"])." ".security::htmlsafe($incident["allday"] ? "(todo el día)" : schedules::sec2time($incident["begins"])."-".schedules::sec2time($incident["ends"]))?></td>
             <td>
               <a href="dynamic/editincidentcomment.php?id=<?=(int)$incident["id"]?>&continue=<?=$safeContinueUrl?>" data-dyndialog-href="dynamic/editincidentcomment.php?id=<?=(int)$incident["id"]?>&continue=<?=$safeContinueUrl?>" class="mdl-button mdl-js-button mdl-button--icon mdl-js-ripple-effect" title="Ver/editar las observaciones"><i class="material-icons icon"><?=(empty($incident["details"]) && empty($incident["workerdetails"]) ? "mode_" : "")?>comment</i></a>
               <span<?=($attachments > 0 ? ' class="mdl-badge mdl-badge--overlap" data-badge="'.$attachments.'"' : '')?>><a href="dynamic/incidentattachments.php?id=<?=(int)$incident["id"]?>&continue=<?=$safeContinueUrl?>" data-dyndialog-href="dynamic/incidentattachments.php?id=<?=(int)$incident["id"]?>&continue=<?=$safeContinueUrl?>" class="mdl-button mdl-js-button mdl-button--icon mdl-js-ripple-effect" title="Ver/gestionar los archivos adjuntos"><i class="material-icons icon">attach_file</i></a></span>
diff --git a/src/inc/registryView.php b/src/inc/registryView.php
index f068558..c0c84f6 100644
--- a/src/inc/registryView.php
+++ b/src/inc/registryView.php
@@ -84,7 +84,7 @@
               <?php
             }
             ?>
-            <td class="can-strike"><?=strftime("%d %b %Y", $record["day"])?></td>
+            <td class="can-strike"><?=date::getShortDate($record["day"])?></td>
             <td class="centered can-strike"><?=schedules::sec2time($record["beginswork"])." - ".schedules::sec2time($record["endswork"])?></td>
             <td class="centered can-strike"><?=(intervals::measure($breakfastInt) == 0 ? "-" : ($isForWorker ? export::sec2hours(intervals::measure($breakfastInt)) : schedules::sec2time($record["beginsbreakfast"])." - ".schedules::sec2time($record["endsbreakfast"])))?></td>
             <td class="centered can-strike"><?=(intervals::measure($lunchInt) == 0 ? "-" : ($isForWorker ? export::sec2hours(intervals::measure($lunchInt)) : schedules::sec2time($record["beginslunch"])." - ".schedules::sec2time($record["endslunch"])))?></td>