diff -r 95dbf5f94ca2 src/core/model/nstime.h
--- a/src/core/model/nstime.h	Sun Apr 07 14:50:51 2013 +0200
+++ b/src/core/model/nstime.h	Sun Apr 07 20:44:34 2013 +0200
@@ -93,13 +93,18 @@
    */
   enum Unit
   {
-    S  = 0,   //!< second
-    MS = 1,   //!< millisecond
-    US = 2,   //!< microsecond
-    NS = 3,   //!< nanosecond
-    PS = 4,   //!< picosecond
-    FS = 5,   //!< femtosecond
-    LAST = 6
+    A   = 0,  //!< year
+    WK  = 1,   //!< week
+    D   = 2,   //!< day
+    H   = 3,   //!< hour
+    MIN = 4,   //!< minute
+    S   = 5,   //!< second
+    MS  = 6,   //!< millisecond
+    US  = 7,   //!< microsecond
+    NS  = 8,   //!< nanosecond
+    PS  = 9,   //!< picosecond
+    FS  = 10,   //!< femtosecond
+    LAST = 11
   };
 
   inline Time &operator = (const Time &o)
@@ -194,6 +199,11 @@
    * - `ns` (nanoseconds)
    * - `ps` (picoseconds)
    * - `fs` (femtoseconds)
+   * - `min`  (minutes)
+   * - `h`  (hours)
+   * - `d`  (days)
+   * - `wk`  (weeks)
+   * - `a`  (years)
    *
    * There can be no white space between the numerical portion
    * and the units.  Any otherwise malformed string causes a fatal error to
@@ -305,6 +315,48 @@
   {
     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 weeks of the time stored in this
+   *          instance.
+   */
+  inline double GetWeeks (void) const
+  {
+    return ToDouble (Time::WK);
+  }
+  /**
+   * \returns an approximation in years of the time stored in this
+   *          instance.
+   */
+  inline double GetYears (void) const
+  {
+    return ToDouble (Time::A);
+  }
+  
   /**
    * \returns the raw time value, in the current units
    */
@@ -678,6 +730,31 @@
   return Time::FromDouble (seconds, Time::S);
 }
 
+inline Time Seconds (float seconds)
+{
+  return Time::FromDouble (seconds, Time::S);
+}
+
+inline Time Seconds (uint64_t seconds)
+{
+  return Time::FromInteger (seconds, Time::S);
+}
+
+inline Time Seconds (int64_t seconds)
+{
+  return Time::FromInteger (seconds, Time::S);
+}
+
+inline Time Seconds (uint32_t seconds)
+{
+  return Time::FromInteger (seconds, Time::S);
+}
+
+inline Time Seconds (int32_t seconds)
+{
+  return Time::FromInteger (seconds, Time::S);
+}
+
 /**
  * \brief create ns3::Time instances in units of milliseconds.
  *
@@ -689,10 +766,36 @@
  * \param ms milliseconds value
  * \relates ns3::Time
  */
+inline Time MilliSeconds (double ms)
+{
+  return Time::FromDouble (ms, Time::MS);
+}
+
+inline Time MilliSeconds (float ms)
+{
+  return Time::FromDouble (ms, Time::MS);
+}
+
 inline Time MilliSeconds (uint64_t ms)
 {
   return Time::FromInteger (ms, Time::MS);
 }
+
+inline Time MilliSeconds (int64_t ms)
+{
+  return Time::FromInteger (ms, Time::MS);
+}
+
+inline Time MilliSeconds (uint32_t ms)
+{
+  return Time::FromInteger (ms, Time::MS);
+}
+
+inline Time MilliSeconds (int32_t ms)
+{
+  return Time::FromInteger (ms, Time::MS);
+}
+
 /**
  * \brief create ns3::Time instances in units of microseconds.
  *
@@ -704,10 +807,36 @@
  * \param us microseconds value
  * \relates ns3::Time
  */
+inline Time MicroSeconds (double us)
+{
+  return Time::FromDouble (us, Time::US);
+}
+
+inline Time MicroSeconds (float us)
+{
+  return Time::FromDouble (us, Time::US);
+}
+
 inline Time MicroSeconds (uint64_t us)
 {
   return Time::FromInteger (us, Time::US);
 }
+
+inline Time MicroSeconds (int64_t us)
+{
+  return Time::FromInteger (us, Time::US);
+}
+
+inline Time MicroSeconds (uint32_t us)
+{
+  return Time::FromInteger (us, Time::US);
+}
+
+inline Time MicroSeconds (int32_t us)
+{
+  return Time::FromInteger (us, Time::US);
+}
+
 /**
  * \brief create ns3::Time instances in units of nanoseconds.
  *
@@ -719,10 +848,36 @@
  * \param ns nanoseconds value
  * \relates ns3::Time
  */
+inline Time NanoSeconds (double ns)
+{
+  return Time::FromDouble (ns, Time::NS);
+}
+
+inline Time NanoSeconds (float ns)
+{
+  return Time::FromDouble (ns, Time::NS);
+}
+
 inline Time NanoSeconds (uint64_t ns)
 {
   return Time::FromInteger (ns, Time::NS);
 }
+
+inline Time NanoSeconds (int64_t ns)
+{
+  return Time::FromInteger (ns, Time::NS);
+}
+
+inline Time NanoSeconds (uint32_t ns)
+{
+  return Time::FromInteger (ns, Time::NS);
+}
+
+inline Time NanoSeconds (int32_t ns)
+{
+  return Time::FromInteger (ns, Time::NS);
+}
+
 /**
  * \brief create ns3::Time instances in units of picoseconds.
  *
@@ -734,10 +889,36 @@
  * \param ps picoseconds value
  * \relates ns3::Time
  */
+inline Time PicoSeconds (double ps)
+{
+  return Time::FromDouble (ps, Time::PS);
+}
+
+inline Time PicoSeconds (float ps)
+{
+  return Time::FromDouble (ps, Time::PS);
+}
+
 inline Time PicoSeconds (uint64_t ps)
 {
   return Time::FromInteger (ps, Time::PS);
 }
+
+inline Time PicoSeconds (int64_t ps)
+{
+  return Time::FromInteger (ps, Time::PS);
+}
+
+inline Time PicoSeconds (uint32_t ps)
+{
+  return Time::FromInteger (ps, Time::PS);
+}
+
+inline Time PicoSeconds (int32_t ps)
+{
+  return Time::FromInteger (ps, Time::PS);
+}
+
 /**
  * \brief create ns3::Time instances in units of femtoseconds.
  *
@@ -749,11 +930,240 @@
  * \param fs femtoseconds value
  * \relates ns3::Time
  */
+inline Time FemtoSeconds (double fs)
+{
+  return Time::FromDouble (fs, Time::FS);
+}
+
+inline Time FemtoSeconds (float fs)
+{
+  return Time::FromDouble (fs, Time::FS);
+}
+
 inline Time FemtoSeconds (uint64_t fs)
 {
   return Time::FromInteger (fs, Time::FS);
 }
 
+inline Time FemtoSeconds (int64_t fs)
+{
+  return Time::FromInteger (fs, Time::FS);
+}
+
+inline Time FemtoSeconds (uint32_t fs)
+{
+  return Time::FromInteger (fs, Time::FS);
+}
+
+inline Time FemtoSeconds (int32_t fs)
+{
+  return Time::FromInteger (fs, Time::FS);
+}
+
+/**
+ * \brief create ns3::Time instances in units of minutes.
+ *
+ * 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);
+}
+
+inline Time Minutes (float minutes)
+{
+  return Time::FromDouble (minutes, Time::MIN);
+}
+
+inline Time Minutes (uint64_t minutes)
+{
+  return Time::FromInteger (minutes, Time::MIN);
+}
+
+inline Time Minutes (int64_t minutes)
+{
+  return Time::FromInteger (minutes, Time::MIN);
+}
+
+inline Time Minutes (uint32_t minutes)
+{
+  return Time::FromInteger (minutes, Time::MIN);
+}
+
+inline Time Minutes (int32_t minutes)
+{
+  return Time::FromInteger (minutes, Time::MIN);
+}
+
+/**
+ * \brief create ns3::Time instances in units of hours.
+ *
+ * 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);
+}
+
+inline Time Hours (float hours)
+{
+  return Time::FromDouble (hours, Time::H);
+}
+
+inline Time Hours (uint64_t hours)
+{
+  return Time::FromInteger (hours, Time::H);
+}
+
+inline Time Hours (int64_t hours)
+{
+  return Time::FromInteger (hours, Time::H);
+}
+
+inline Time Hours (uint32_t hours)
+{
+  return Time::FromInteger (hours, Time::H);
+}
+
+inline Time Hours (int32_t hours)
+{
+  return Time::FromInteger (hours, Time::H);
+}
+
+/**
+ * \brief create ns3::Time instances in units of days.
+ *
+ * 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);
+}
+
+inline Time Days (float days)
+{
+  return Time::FromDouble (days, Time::D);
+}
+
+inline Time Days (uint64_t days)
+{
+  return Time::FromInteger (days, Time::D);
+}
+
+inline Time Days (int64_t days)
+{
+  return Time::FromInteger (days, Time::D);
+}
+
+inline Time Days (uint32_t days)
+{
+  return Time::FromInteger (days, Time::D);
+}
+
+inline Time Days (int32_t days)
+{
+  return Time::FromInteger (days, Time::D);
+}
+
+/**
+ * \brief create ns3::Time instances in units of weeks.
+ *
+ * For example:
+ * \code
+ * Time t = Weeks (2.0);
+ * Simulator::Schedule (Weeks (5.0), ...);
+ * \endcode
+ * \param weeks weeks value
+ * \relates ns3::Time
+ */
+inline Time Weeks (double weeks)
+{
+  return Time::FromDouble (weeks, Time::WK);
+}
+
+inline Time Weeks (float weeks)
+{
+  return Time::FromDouble (weeks, Time::WK);
+}
+
+inline Time Weeks (uint64_t weeks)
+{
+  return Time::FromInteger (weeks, Time::WK);
+}
+
+inline Time Weeks (int64_t weeks)
+{
+  return Time::FromInteger (weeks, Time::WK);
+}
+
+inline Time Weeks (uint32_t weeks)
+{
+  return Time::FromInteger (weeks, Time::WK);
+}
+
+inline Time Weeks (int32_t weeks)
+{
+  return Time::FromInteger (weeks, Time::WK);
+}
+
+/**
+ * \brief create ns3::Time instances in units of years.
+ *
+ * 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::A);
+}
+
+inline Time Years (float years)
+{
+  return Time::FromDouble (years, Time::A);
+}
+
+inline Time Years (uint64_t years)
+{
+  return Time::FromInteger (years, Time::A);
+}
+
+inline Time Years (int64_t years)
+{
+  return Time::FromInteger (years, Time::A);
+}
+
+inline Time Years (uint32_t years)
+{
+  return Time::FromInteger (years, Time::A);
+}
+
+inline Time Years (int32_t years)
+{
+  return Time::FromInteger (years, Time::A);
+}
 
 /**
  * \see Seconds(double)
@@ -803,6 +1213,46 @@
 {
   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 Weeks (int64x64_t weeks)
+{
+  return Time::From (weeks, Time::WK);
+}
+/**
+ * \see Minutes(uint64_t)
+ * \relates ns3::Time
+ */ 
+inline Time Years (int64x64_t years)
+{
+  return Time::From (years, Time::A);
+}
 
 // internal function not publicly documented
 inline Time TimeStep (uint64_t ts)
diff -r 95dbf5f94ca2 src/core/model/time.cc
--- a/src/core/model/time.cc	Sun Apr 07 14:50:51 2013 +0200
+++ b/src/core/model/time.cc	Sun Apr 07 20:44:34 2013 +0200
@@ -102,6 +102,30 @@
         {
           *this = Time::FromDouble (r, Time::FS);
         }
+      else if (trailer == std::string ("fs"))
+        {
+          *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 ("wk"))
+        {
+          *this = Time::FromDouble (r, Time::WK);
+        }
+      else if (trailer == std::string ("a"))
+        {
+          *this = Time::FromDouble (r, Time::A);
+        }
       else
         {
           NS_ABORT_MSG ("Can't Parse Time " << s);
@@ -153,21 +177,39 @@
       ConvertTimes (unit);
     }
   
-  int8_t power [LAST] = { 15, 12, 9, 6, 3, 0};
+  // A, WK, D, H, MIN, S, MS, US, NS, PS, FS
+  const int8_t power [LAST] = { 17, 17, 17, 17, 16, 15, 12, 9, 6, 3, 0 };
+  const int32_t coefficient [LAST] = { 315576, 6048, 864, 36, 6, 1, 1, 1, 1, 1, 1 };
   for (int i = 0; i < Time::LAST; i++)
     {
       int shift = power[i] - power[(int)unit];
-      uint64_t factor = (uint64_t) std::pow (10, std::fabs (shift));
+      int quotient = 1;
+      if (coefficient[i] > coefficient[(int) unit])
+        {
+          quotient = coefficient[i] / coefficient[(int) unit];
+        }
+      else if (coefficient[i] < coefficient[(int) unit])
+        {
+          quotient = -coefficient[(int) unit] / coefficient[i];
+        }
+      NS_LOG_DEBUG ("SetResolution for unit " << (int) unit <<  " loop iteration " << i
+                    << " has shift " << shift << " has quotient " << quotient);
+      uint64_t factor = (uint64_t) std::pow (10, std::fabs (shift)) * std::fabs (quotient);
+      double realFactor = std::pow (10, 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);
@@ -176,7 +218,7 @@
         }
       else
         {
-          NS_ASSERT (shift < 0);
+          NS_ASSERT (realFactor < 1);
           info->timeFrom = int64x64_t::Invert (factor);
           info->timeTo = int64x64_t (factor);
           info->toMul = true;
@@ -308,6 +350,21 @@
     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::WK:
+      unit = "wk";
+      break;
+    case Time::A:
+      unit = "a";
+      break;
     case Time::LAST:
       NS_ABORT_MSG ("can't be reached");
       unit = "unreachable";