Add KADateTime::msecsTo()

src/kadatetime.cpp

@@ -1240,6 +1240,20 @@ KADateTime KADateTime::addYears(int years) const
     return result;
 }
 
+qint64 KADateTime::msecsTo(const KADateTime &t2) const
+{
+    if (!isValid() || !t2.isValid())
+        return 0;
+    if (d->dateOnly()) {
+        const QDate dat = t2.d->dateOnly() ? t2.d->date() : t2.toTimeSpec(d->spec()).d->date();
+        return d->date().daysTo(dat) * 86400*1000;
+    }
+    if (t2.d->dateOnly())
+        return toTimeSpec(t2.d->spec()).d->date().daysTo(t2.d->date()) * 86400*1000;
+    QTimeZone local;
+    return d->toUtc(local).msecsTo(t2.d->toUtc(local));
+}
+
 qint64 KADateTime::secsTo(const KADateTime &t2) const
 {
     if (!isValid() || !t2.isValid())

src/kadatetime.h

@@ -921,6 +921,27 @@ public:
      */
     KADateTime addYears(int years) const;
 
+    /**
+     * Returns the number of milliseconds from this date/time to the @p other date/time.
+     *
+     * Before performing the comparison, the two date/times are converted to UTC
+     * to ensure that the result is correct if one of the two date/times has
+     * daylight saving time (DST) and the other doesn't.
+     *
+     * If one instance is date-only and the other is date-time, the date-time
+     * value is first converted to the same time specification as the date-only
+     * value, and the result is the difference in days between the resultant
+     * date and the date-only date.
+     *
+     * If both instances are date-only, the result is the difference in days
+     * between the two dates, ignoring time zones.
+     *
+     * @param other other date/time
+     * @return number of milliseconds difference
+     * @see addSecs(), daysTo()
+     */
+    qint64 msecsTo(const KADateTime &other) const;
+
     /**
      * Returns the number of seconds from this date/time to the @p other date/time.
      *