diff --git a/src/core/model/nstime.h b/src/core/model/nstime.h
index 202bbc38e..ee33f2e87 100644
--- a/src/core/model/nstime.h
+++ b/src/core/model/nstime.h
@@ -86,13 +86,17 @@ public:
    */
   enum Unit
   {
-    S  = 0,   //!< second
-    MS = 1,   //!< millisecond
-    US = 2,   //!< microsecond
-    NS = 3,   //!< nanosecond
-    PS = 4,   //!< picosecond
-    FS = 5,   //!< femtosecond
-    LAST = 6
+    Y   = 0,   //!< year, 365 days
+    D   = 1,   //!< day, 24 hours
+    H   = 2,   //!< hour, 60 minutes
+    MIN = 3,   //!< minute, 60 seconds
+    S   = 4,   //!< second
+    MS  = 5,   //!< millisecond
+    US  = 6,   //!< microsecond
+    NS  = 7,   //!< nanosecond
+    PS  = 8,   //!< picosecond
+    FS  = 9,   //!< femtosecond
+    LAST = 10
   };
 
   inline Time &operator = (const Time &o)
@@ -182,6 +186,10 @@ public:
    * - `ns` (nanoseconds)
    * - `ps` (picoseconds)
    * - `fs` (femtoseconds)
+   * - `min`  (minutes)
+   * - `h`  (hours)
+   * - `d`  (days)
+   * - `y`  (years)
    *
    * There can be no white space between the numerical portion
    * and the units.  Any otherwise malformed string causes a fatal error to
@@ -308,6 +316,40 @@ public:
   {
     return ToInteger (Time::FS);
   }
+
+  /**
+   * \returns an approximation in minutes of the time stored in this
+   *          instance.
+   */
+  inline double GetMinutes (void) const
+  {
+    return ToDouble (Time::MIN);
+  }
+  /**
+   * \returns an approximation in hours of the time stored in this
+   *          instance.
+   */
+  inline double GetHours (void) const
+  {
+    return ToDouble (Time::H);
+  }
+  /**
+   * \returns an approximation in days of the time stored in this
+   *          instance.
+   */
+  inline double GetDays (void) const
+  {
+    return ToDouble (Time::D);
+  }
+  /**
+   * \returns an approximation in years of the time stored in this
+   *          instance.
+   */
+  inline double GetYears (void) const
+  {
+    return ToDouble (Time::Y);
+  }
+
   /**
    * \returns the raw time value, in the current units
    */
@@ -762,7 +804,66 @@ inline Time FemtoSeconds (uint64_t fs)
 {
   return Time::FromInteger (fs, Time::FS);
 }
-
+/**
+ * \brief create ns3::Time instances in units of minutes (equal to 60 seconds).
+ *
+ * For example:
+ * \code
+ * Time t = Minutes (2.0);
+ * Simulator::Schedule (Minutes (5.0), ...);
+ * \endcode
+ * \param minutes mintues value
+ * \relates ns3::Time
+ */
+inline Time Minutes (double minutes)
+{
+  return Time::FromDouble (minutes, Time::MIN);
+}
+/**
+ * \brief create ns3::Time instances in units of hours (equal to 60 minutes).
+ *
+ * For example:
+ * \code
+ * Time t = Hours (2.0);
+ * Simulator::Schedule (Hours (5.0), ...);
+ * \endcode
+ * \param hours hours value
+ * \relates ns3::Time
+ */
+inline Time Hours (double hours)
+{
+  return Time::FromDouble (hours, Time::H);
+}
+/**
+ * \brief create ns3::Time instances in units of days (equal to 24 hours).
+ *
+ * For example:
+ * \code
+ * Time t = Days (2.0);
+ * Simulator::Schedule (Days (5.0), ...);
+ * \endcode
+ * \param days days value
+ * \relates ns3::Time
+ */
+inline Time Days (double days)
+{
+  return Time::FromDouble (days, Time::D);
+}
+/**
+ * \brief create ns3::Time instances in units of years (equal to 365 days).
+ *
+ * For example:
+ * \code
+ * Time t = Years (2.0);
+ * Simulator::Schedule (Years (5.0), ...);
+ * \endcode
+ * \param years years value
+ * \relates ns3::Time
+ */
+inline Time Years (double years)
+{
+  return Time::FromDouble (years, Time::Y);
+}
 
 /**
  * \see Seconds(double)
@@ -812,6 +913,38 @@ inline Time FemtoSeconds (int64x64_t fs)
 {
   return Time::From (fs, Time::FS);
 }
+/**
+ * \see Minutes(uint64_t)
+ * \relates ns3::Time
+ */
+inline Time Minutes (int64x64_t minutes)
+{
+  return Time::From (minutes, Time::MIN);
+}
+/**
+ * \see Minutes(uint64_t)
+ * \relates ns3::Time
+ */
+inline Time Hours (int64x64_t hours)
+{
+  return Time::From (hours, Time::H);
+}
+/**
+ * \see Minutes(uint64_t)
+ * \relates ns3::Time
+ */
+inline Time Days (int64x64_t days)
+{
+  return Time::From (days, Time::D);
+}
+/**
+ * \see Minutes(uint64_t)
+ * \relates ns3::Time
+ */
+inline Time Years (int64x64_t years)
+{
+  return Time::From (years, Time::Y);
+}
 
 // internal function not publicly documented
 inline Time TimeStep (uint64_t ts)
diff --git a/src/core/model/time.cc b/src/core/model/time.cc
index 03a54ffff..a2e02a9df 100644
--- a/src/core/model/time.cc
+++ b/src/core/model/time.cc
@@ -123,6 +123,22 @@ Time::Time (const std::string& s)
         {
           *this = Time::FromDouble (r, Time::FS);
         }
+      else if (trailer == std::string ("min"))
+        {
+          *this = Time::FromDouble (r, Time::MIN);
+        }
+      else if (trailer == std::string ("h"))
+        {
+          *this = Time::FromDouble (r, Time::H);
+        }
+      else if (trailer == std::string ("d"))
+        {
+          *this = Time::FromDouble (r, Time::D);
+        }
+      else if (trailer == std::string ("y"))
+        {
+          *this = Time::FromDouble (r, Time::Y);
+        }
       else
         {
           NS_ABORT_MSG ("Can't Parse Time " << s);
@@ -176,21 +192,41 @@ Time::SetResolution (enum Unit unit, struct Resolution *resolution,
       ConvertTimes (unit);
     }
 
-  int8_t power [LAST] = { 15, 12, 9, 6, 3, 0};
+  // Y, D, H, MIN, S, MS, US, NS, PS, FS
+  const int8_t power [LAST] = { 17, 17, 17, 16, 15, 12, 9, 6, 3, 0 };
+  const int32_t coefficient [LAST] = { 315360, 864, 36, 6, 1, 1, 1, 1, 1, 1 };
   for (int i = 0; i < Time::LAST; i++)
     {
       int shift = power[i] - power[(int)unit];
-      int64_t factor = (int64_t) std::pow (10, std::fabs (shift));
+      int quotient = 1;
+      if (coefficient[i] > coefficient[(int) unit])
+        {
+          quotient = coefficient[i] / coefficient[(int) unit];
+          NS_ASSERT (quotient * coefficient[(int) unit] == coefficient[i]);
+        }
+      else if (coefficient[i] < coefficient[(int) unit])
+        {
+          quotient = coefficient[(int) unit] / coefficient[i];
+          NS_ASSERT (quotient * coefficient[i] == coefficient[(int) unit]);
+        }
+      NS_LOG_DEBUG ("SetResolution for unit " << (int) unit << " loop iteration " << i
+    		    << " has shift " << shift << " has quotient " << quotient);
+      int64_t factor = static_cast<int64_t> (std::pow (10, std::fabs (shift)) * quotient);
+      double realFactor = std::pow (10, (double) shift)
+                        * static_cast<double> (coefficient[i]) / coefficient[(int) unit];
+      NS_LOG_DEBUG ("SetResolution factor " << factor << " real factor " << realFactor);
       struct Information *info = &resolution->info[i];
       info->factor = factor;
-      if (shift == 0)
+      // here we could equivalently check for realFactor == 1.0 but it's better
+      // to avoid checking equality of doubles
+      if (shift == 0 && quotient == 1)
         {
           info->timeFrom = int64x64_t (1);
           info->timeTo = int64x64_t (1);
           info->toMul = true;
           info->fromMul = true;
         }
-      else if (shift > 0)
+      else if (realFactor > 1)
         {
           info->timeFrom = int64x64_t (factor);
           info->timeTo = int64x64_t::Invert (factor);
@@ -199,7 +235,7 @@ Time::SetResolution (enum Unit unit, struct Resolution *resolution,
         }
       else
         {
-          NS_ASSERT (shift < 0);
+          NS_ASSERT (realFactor < 1);
           info->timeFrom = int64x64_t::Invert (factor);
           info->timeTo = int64x64_t (factor);
           info->toMul = true;
@@ -368,6 +404,18 @@ operator<< (std::ostream& os, const Time & time)
     case Time::FS:
       unit = "fs";
       break;
+    case Time::MIN:
+      unit = "min";
+      break;
+    case Time::H:
+      unit = "h";
+      break;
+    case Time::D:
+      unit = "d";
+      break;
+    case Time::Y:
+      unit = "y";
+      break;
     case Time::LAST:
       NS_ABORT_MSG ("can't be reached");
       unit = "unreachable";
diff --git a/src/core/test/time-test-suite.cc b/src/core/test/time-test-suite.cc
index a875a1aa4..88b1b8348 100644
--- a/src/core/test/time-test-suite.cc
+++ b/src/core/test/time-test-suite.cc
@@ -47,6 +47,22 @@ TimeSimpleTestCase::DoSetup (void)
 void
 TimeSimpleTestCase::DoRun (void)
 {
+  NS_TEST_ASSERT_MSG_EQ_TOL (Years (1.0).GetYears (), 1.0, Years (1).GetYears (),
+                             "is 1 really 1 ?");
+  NS_TEST_ASSERT_MSG_EQ_TOL (Years (10.0).GetYears (), 10.0, Years (1).GetYears (),
+                             "is 10 really 10 ?");
+  NS_TEST_ASSERT_MSG_EQ_TOL (Days (1.0).GetDays (), 1.0, Days (1).GetDays (),
+                             "is 1 really 1 ?");
+  NS_TEST_ASSERT_MSG_EQ_TOL (Days (10.0).GetDays (), 10.0, Days (1).GetDays (),
+                             "is 10 really 10 ?");
+  NS_TEST_ASSERT_MSG_EQ_TOL (Hours (1.0).GetHours (), 1.0, Hours (1).GetHours (),
+                             "is 1 really 1 ?");
+  NS_TEST_ASSERT_MSG_EQ_TOL (Hours (10.0).GetHours (), 10.0, Hours (1).GetHours (),
+                             "is 10 really 10 ?");
+  NS_TEST_ASSERT_MSG_EQ_TOL (Minutes (1.0).GetMinutes (), 1.0, Minutes (1).GetMinutes (),
+                             "is 1 really 1 ?");
+  NS_TEST_ASSERT_MSG_EQ_TOL (Minutes (10.0).GetMinutes (), 10.0, Minutes (1).GetMinutes (),
+                             "is 10 really 10 ?");
   NS_TEST_ASSERT_MSG_EQ_TOL (Seconds (1.0).GetSeconds (), 1.0, TimeStep (1).GetSeconds (), 
                              "is 1 really 1 ?");
   NS_TEST_ASSERT_MSG_EQ_TOL (Seconds (10.0).GetSeconds (), 10.0, TimeStep (1).GetSeconds (),