diff --git a/library/core/src/time.rs b/library/core/src/time.rs
index d66f558078ea8..9dc4d39ae4e95 100644
--- a/library/core/src/time.rs
+++ b/library/core/src/time.rs
@@ -101,6 +101,66 @@ pub struct Duration {
 }
 
 impl Duration {
+    /// The duration of one week.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(duration_constructors)]
+    /// use std::time::Duration;
+    ///
+    /// assert_eq!(Duration::WEEK, Duration::from_weeks(1));
+    /// assert_eq!(5 * Duration::WEEK, Duration::from_weeks(5));
+    /// assert_eq!(Duration::WEEK, Duration::from_secs(7 * 24 * 60 * 60));
+    /// ```
+    #[unstable(feature = "duration_constructors", issue = "120301")]
+    pub const WEEK: Duration = Duration::from_weeks(1);
+
+    /// The duration of one day.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(duration_constructors)]
+    /// use std::time::Duration;
+    ///
+    /// assert_eq!(Duration::DAY, Duration::from_days(1));
+    /// assert_eq!(5 * Duration::DAY, Duration::from_days(5));
+    /// assert_eq!(Duration::DAY, Duration::from_secs(24 * 60 * 60));
+    /// ```
+    #[unstable(feature = "duration_constructors", issue = "120301")]
+    pub const DAY: Duration = Duration::from_days(1);
+
+    /// The duration of one hour.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(duration_constructors)]
+    /// use std::time::Duration;
+    ///
+    /// assert_eq!(Duration::HOUR, Duration::from_hours(1));
+    /// assert_eq!(5 * Duration::HOUR, Duration::from_hours(5));
+    /// assert_eq!(Duration::HOUR, Duration::from_secs(60 * 60));
+    /// ```
+    #[unstable(feature = "duration_constructors", issue = "120301")]
+    pub const HOUR: Duration = Duration::from_hours(1);
+
+    /// The duration of one minute.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(duration_constructors)]
+    /// use std::time::Duration;
+    ///
+    /// assert_eq!(Duration::MINUTE, Duration::from_mins(1));
+    /// assert_eq!(5 * Duration::MINUTE, Duration::from_mins(5));
+    /// assert_eq!(Duration::MINUTE, Duration::from_secs(60));
+    /// ```
+    #[unstable(feature = "duration_constructors", issue = "120301")]
+    pub const MINUTE: Duration = Duration::from_mins(1);
+
     /// The duration of one second.
     ///
     /// # Examples