Add From<NaiveDate> for NaiveDateTime

src/naive/datetime/mod.rs

@@ -1048,6 +1048,22 @@ impl NaiveDateTime {
         expect!(NaiveDate::from_ymd_opt(1970, 1, 1), "").and_time(NaiveTime::MIN);
 }
 
+impl From<NaiveDate> for NaiveDateTime {
+    /// Converts a `NaiveDate` to a `NaiveDateTime` of the same date but at midnight.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use chrono::{NaiveDate, NaiveDateTime};
+    ///
+    /// let nd = NaiveDate::from_ymd_opt(2016, 5, 28).unwrap();
+    /// let ndt = NaiveDate::from_ymd_opt(2016, 5, 28).unwrap().and_hms_opt(0, 0, 0).unwrap();
+    /// assert_eq!(ndt, NaiveDateTime::from(nd));
+    fn from(date: NaiveDate) -> Self {
+        date.and_hms_opt(0, 0, 0).unwrap()
+    }
+}
+
 impl Datelike for NaiveDateTime {
     /// Returns the year number in the [calendar date](./struct.NaiveDate.html#calendar-date).
     ///