diff --git a/chrono/datetime.cpp b/chrono/datetime.cpp
index 93d5f07..67a2d78 100644
--- a/chrono/datetime.cpp
+++ b/chrono/datetime.cpp
@@ -110,9 +110,9 @@ DateTime DateTime::fromString(const char *str)
 }
 
 /*!
- * \brief Parses the given ISO date time denotation provided as C-style string.
- * \returns Returns a pair where the first value is the parsed UTC DateTime and the second value
- *          a TimeSpan which can be added to the first value to get the local DateTime.
+ * \brief Parses the specified ISO date time denotation provided as C-style string.
+ * \returns Returns a pair where the first value is the parsed date time and the second value
+ *          a time span which can be subtracted from the first value to get the UTC time.
  * \remarks Not sure whether it is actually ISO conform, but it parses denotations like
  *          "2016-08-29T21:32:31.588539814+02:00".
  */
@@ -297,7 +297,7 @@ uint64 DateTime::dateToTicks(int year, int month, int day)
             if(inRangeInclMax(day, 1, daysToMonth[month] - daysToMonth[passedMonth])) {
                 int passedYears = year - 1;
                 int passedDays = day - 1;
-                return (passedYears * m_daysPerYear + passedYears / 4 - passedYears / 100 + passedYears / 400 + daysToMonth[passedMonth] + passedDays) * TimeSpan::m_ticksPerDay;
+                return (passedYears * m_daysPerYear + passedYears / 4 - passedYears / 100 + passedYears / 400 + daysToMonth[passedMonth] + passedDays) * TimeSpan::ticksPerDay;
             } else {
                 throw ConversionException("day is out of range");
             }
@@ -327,7 +327,7 @@ uint64 DateTime::timeToTicks(int hour, int minute, int second, double millisecon
     if(!inRangeExclMax(millisecond, 0.0, 1000.0)) {
         throw ConversionException("millisecond is out of range");
     }
-    return (hour * TimeSpan::m_ticksPerHour) + (minute * TimeSpan::m_ticksPerMinute) + (second * TimeSpan::m_ticksPerSecond) + (uint64)(millisecond * (double)TimeSpan::m_ticksPerMillisecond);
+    return (hour * TimeSpan::ticksPerHour) + (minute * TimeSpan::ticksPerMinute) + (second * TimeSpan::ticksPerSecond) + (uint64)(millisecond * (double)TimeSpan::ticksPerMillisecond);
 }
 
 /*!
@@ -336,7 +336,7 @@ uint64 DateTime::timeToTicks(int hour, int minute, int second, double millisecon
  */
 int DateTime::getDatePart(DatePart part) const
 {
-    int fullDays = m_ticks / TimeSpan::m_ticksPerDay;
+    int fullDays = m_ticks / TimeSpan::ticksPerDay;
     int full400YearBlocks = fullDays / m_daysPer400Years;
     int daysMinusFull400YearBlocks = fullDays - full400YearBlocks * m_daysPer400Years;
     int full100YearBlocks = daysMinusFull400YearBlocks / m_daysPer100Years;
diff --git a/chrono/datetime.h b/chrono/datetime.h
index 7f96160..a7fc363 100644
--- a/chrono/datetime.h
+++ b/chrono/datetime.h
@@ -63,6 +63,8 @@ public:
     static DateTime fromString(const std::string &str);
     static DateTime fromString(const char *str);
     static std::pair<DateTime, TimeSpan> fromIsoString(const char *str);
+    static DateTime fromIsoStringGmt(const char *str);
+    static DateTime fromIsoStringLocal(const char *str);
     static DateTime fromTimeStamp(time_t timeStamp);
     static DateTime fromTimeStampGmt(time_t timeStamp);
 
@@ -83,7 +85,7 @@ public:
     constexpr bool isSameDay(const DateTime &other) const;
     std::string toString(DateTimeOutputFormat format = DateTimeOutputFormat::DateAndTime, bool noMilliseconds = false) const;
     void toString(std::string &result, DateTimeOutputFormat format = DateTimeOutputFormat::DateAndTime, bool noMilliseconds = false) const;
-    std::string toIsoString(TimeSpan delta) const;
+    std::string toIsoString(TimeSpan timeZoneDelta = TimeSpan()) const;
     static const char *printDayOfWeek(DayOfWeek dayOfWeek, bool abbreviation = false);
 
     static constexpr DateTime eternity();
@@ -175,6 +177,27 @@ inline DateTime DateTime::fromString(const std::string &str)
     return fromString(str.data());
 }
 
+/*!
+ * \brief Parses the specified ISO date time denotation provided as C-style string.
+ * \returns Returns the parsed UTC time. That means a possibly denoted time zone delta is subtracted from the time stamp.
+ * \sa fromIsoString()
+ */
+inline DateTime DateTime::fromIsoStringGmt(const char *str)
+{
+    const auto tmp = fromIsoString(str);
+    return tmp.first - tmp.second;
+}
+
+/*!
+ * \brief Parses the specified ISO date time denotation provided as C-style string.
+ * \returns Returns the parsed local time. That means a possibly denoted time zone delta is discarded.
+ * \sa fromIsoString()
+ */
+inline DateTime DateTime::fromIsoStringLocal(const char *str)
+{
+    return fromIsoString(str).first;
+}
+
 /*!
  * \brief Gets the number of ticks which represent the value of the current instance.
  */
@@ -221,7 +244,7 @@ inline int DateTime::dayOfYear() const
  */
 constexpr inline DayOfWeek DateTime::dayOfWeek() const
 {
-    return static_cast<DayOfWeek>((m_ticks / TimeSpan::m_ticksPerDay) % 7l);
+    return static_cast<DayOfWeek>((m_ticks / TimeSpan::ticksPerDay) % 7l);
 }
 
 /*!
@@ -229,7 +252,7 @@ constexpr inline DayOfWeek DateTime::dayOfWeek() const
  */
 constexpr inline int DateTime::hour() const
 {
-    return m_ticks / TimeSpan::m_ticksPerHour % 24ul;
+    return m_ticks / TimeSpan::ticksPerHour % 24ul;
 }
 
 /*!
@@ -237,7 +260,7 @@ constexpr inline int DateTime::hour() const
  */
 constexpr inline int DateTime::minute() const
 {
-    return m_ticks / TimeSpan::m_ticksPerMinute % 60ul;
+    return m_ticks / TimeSpan::ticksPerMinute % 60ul;
 }
 
 /*!
@@ -245,7 +268,7 @@ constexpr inline int DateTime::minute() const
  */
 constexpr inline int DateTime::second() const
 {
-    return m_ticks / TimeSpan::m_ticksPerSecond % 60ul;
+    return m_ticks / TimeSpan::ticksPerSecond % 60ul;
 }
 
 /*!
@@ -253,7 +276,7 @@ constexpr inline int DateTime::second() const
  */
 constexpr inline int DateTime::millisecond() const
 {
-    return m_ticks / TimeSpan::m_ticksPerMillisecond % 1000ul;
+    return m_ticks / TimeSpan::ticksPerMillisecond % 1000ul;
 }
 
 /*!
@@ -270,7 +293,7 @@ constexpr inline bool DateTime::isNull() const
  */
 constexpr inline TimeSpan DateTime::timeOfDay() const
 {
-    return TimeSpan(m_ticks % TimeSpan::m_ticksPerDay);
+    return TimeSpan(m_ticks % TimeSpan::ticksPerDay);
 }
 
 /*!
@@ -318,7 +341,7 @@ inline int DateTime::daysInMonth(int year, int month)
  */
 constexpr inline bool DateTime::isSameDay(const DateTime &other) const
 {
-    return (m_ticks / TimeSpan::m_ticksPerDay) == (other.m_ticks / TimeSpan::m_ticksPerDay);
+    return (m_ticks / TimeSpan::ticksPerDay) == (other.m_ticks / TimeSpan::ticksPerDay);
 }
 
 /*!
diff --git a/chrono/timespan.h b/chrono/timespan.h
index 12efb9b..109bee7 100644
--- a/chrono/timespan.h
+++ b/chrono/timespan.h
@@ -73,13 +73,14 @@ public:
     constexpr bool isNegativeInfinity() const;
     constexpr bool isInfinity() const;
 
+    static constexpr uint64 ticksPerMillisecond = 10000uL;
+    static constexpr uint64 ticksPerSecond = 10000000uL;
+    static constexpr uint64 ticksPerMinute = 600000000uL;
+    static constexpr uint64 ticksPerHour = 36000000000uL;
+    static constexpr uint64 ticksPerDay = 864000000000uL;
+
 private:
     int64 m_ticks;
-    static constexpr uint64 m_ticksPerMillisecond = 10000uL;
-    static constexpr uint64 m_ticksPerSecond = 10000000uL;
-    static constexpr uint64 m_ticksPerMinute = 600000000uL;
-    static constexpr uint64 m_ticksPerHour = 36000000000uL;
-    static constexpr uint64 m_ticksPerDay = 864000000000uL;
 };
 
 /*!
@@ -99,7 +100,7 @@ constexpr inline TimeSpan::TimeSpan(int64 ticks) : m_ticks(ticks)
  */
 constexpr inline TimeSpan TimeSpan::fromMilliseconds(double milliseconds)
 {
-    return TimeSpan(static_cast<int64>(milliseconds * static_cast<double>(m_ticksPerMillisecond)));
+    return TimeSpan(static_cast<int64>(milliseconds * static_cast<double>(ticksPerMillisecond)));
 }
 
 /*!
@@ -107,7 +108,7 @@ constexpr inline TimeSpan TimeSpan::fromMilliseconds(double milliseconds)
  */
 constexpr inline TimeSpan TimeSpan::fromSeconds(double seconds)
 {
-    return TimeSpan(static_cast<int64>(seconds * static_cast<double>(m_ticksPerSecond)));
+    return TimeSpan(static_cast<int64>(seconds * static_cast<double>(ticksPerSecond)));
 }
 
 /*!
@@ -115,7 +116,7 @@ constexpr inline TimeSpan TimeSpan::fromSeconds(double seconds)
  */
 constexpr inline TimeSpan TimeSpan::fromMinutes(double minutes)
 {
-    return TimeSpan(static_cast<int64>(minutes * static_cast<double>(m_ticksPerMinute)));
+    return TimeSpan(static_cast<int64>(minutes * static_cast<double>(ticksPerMinute)));
 }
 
 /*!
@@ -123,7 +124,7 @@ constexpr inline TimeSpan TimeSpan::fromMinutes(double minutes)
  */
 constexpr inline TimeSpan TimeSpan::fromHours(double hours)
 {
-    return TimeSpan(static_cast<int64>(hours * static_cast<double>(m_ticksPerHour)));
+    return TimeSpan(static_cast<int64>(hours * static_cast<double>(ticksPerHour)));
 }
 
 /*!
@@ -131,7 +132,7 @@ constexpr inline TimeSpan TimeSpan::fromHours(double hours)
  */
 constexpr inline TimeSpan TimeSpan::fromDays(double days)
 {
-    return TimeSpan(static_cast<int64>(days * static_cast<double>(m_ticksPerDay)));
+    return TimeSpan(static_cast<int64>(days * static_cast<double>(ticksPerDay)));
 }
 
 /*!
@@ -171,7 +172,7 @@ constexpr inline int64 TimeSpan::totalTicks() const
  */
 constexpr inline double TimeSpan::totalMilliseconds() const
 {
-    return static_cast<double>(m_ticks) / static_cast<double>(m_ticksPerMillisecond);
+    return static_cast<double>(m_ticks) / static_cast<double>(ticksPerMillisecond);
 }
 
 /*!
@@ -179,7 +180,7 @@ constexpr inline double TimeSpan::totalMilliseconds() const
  */
 constexpr inline double TimeSpan::totalSeconds() const
 {
-    return static_cast<double>(m_ticks) / static_cast<double>(m_ticksPerSecond);
+    return static_cast<double>(m_ticks) / static_cast<double>(ticksPerSecond);
 }
 
 /*!
@@ -187,7 +188,7 @@ constexpr inline double TimeSpan::totalSeconds() const
  */
 constexpr inline double TimeSpan::totalMinutes() const
 {
-    return static_cast<double>(m_ticks) / static_cast<double>(m_ticksPerMinute);
+    return static_cast<double>(m_ticks) / static_cast<double>(ticksPerMinute);
 }
 
 /*!
@@ -195,7 +196,7 @@ constexpr inline double TimeSpan::totalMinutes() const
  */
 constexpr inline double TimeSpan::totalHours() const
 {
-    return static_cast<double>(m_ticks) / static_cast<double>(m_ticksPerHour);
+    return static_cast<double>(m_ticks) / static_cast<double>(ticksPerHour);
 }
 
 /*!
@@ -203,7 +204,7 @@ constexpr inline double TimeSpan::totalHours() const
  */
 constexpr inline double TimeSpan::totalDays() const
 {
-    return static_cast<double>(m_ticks) / static_cast<double>(m_ticksPerDay);
+    return static_cast<double>(m_ticks) / static_cast<double>(ticksPerDay);
 }
 
 /*!
@@ -211,7 +212,7 @@ constexpr inline double TimeSpan::totalDays() const
  */
 constexpr inline int TimeSpan::milliseconds() const
 {
-    return (m_ticks / m_ticksPerMillisecond) % 1000l;
+    return (m_ticks / ticksPerMillisecond) % 1000l;
 }
 
 /*!
@@ -219,7 +220,7 @@ constexpr inline int TimeSpan::milliseconds() const
  */
 constexpr inline int TimeSpan::seconds() const
 {
-    return (m_ticks / m_ticksPerSecond) % 60l;
+    return (m_ticks / ticksPerSecond) % 60l;
 }
 
 /*!
@@ -227,7 +228,7 @@ constexpr inline int TimeSpan::seconds() const
  */
 constexpr inline int TimeSpan::minutes() const
 {
-    return (m_ticks / m_ticksPerMinute) % 60l;
+    return (m_ticks / ticksPerMinute) % 60l;
 }
 
 /*!
@@ -235,7 +236,7 @@ constexpr inline int TimeSpan::minutes() const
  */
 constexpr inline int TimeSpan::hours() const
 {
-    return (m_ticks / m_ticksPerHour) % 24l;
+    return (m_ticks / ticksPerHour) % 24l;
 }
 
 /*!
@@ -243,7 +244,7 @@ constexpr inline int TimeSpan::hours() const
  */
 constexpr inline int TimeSpan::days() const
 {
-    return (m_ticks / m_ticksPerDay);
+    return (m_ticks / ticksPerDay);
 }
 
 /*!