Add MIN and MAX DateTime, Time and NaiveDateTime (chronotope#452)

Resolves chronotope#386

CHANGELOG.md

@@ -10,6 +10,10 @@ Versions with only mechanical changes will be omitted from the following list.
 
 ## 0.4.14 (unreleased)
 
+## Improvements
+
+* Added MIN and MAX values for `NaiveTime`, `NaiveDateTime` and `DateTime<Utc>`.
+
 
 ## 0.4.13
 

src/datetime.rs

@@ -21,7 +21,7 @@ use core::borrow::Borrow;
 use format::DelayedFormat;
 use format::{parse, ParseError, ParseResult, Parsed, StrftimeItems};
 use format::{Fixed, Item};
-use naive::{IsoWeek, NaiveDateTime, NaiveTime};
+use naive::{self, IsoWeek, NaiveDateTime, NaiveTime};
 #[cfg(feature = "clock")]
 use offset::Local;
 use offset::{FixedOffset, Offset, TimeZone, Utc};
@@ -70,6 +70,11 @@ pub struct DateTime<Tz: TimeZone> {
     offset: Tz::Offset,
 }
 
+/// The minimum possilbe `DateTime<Utc>`.
+pub const MIN_DATETIME: DateTime<Utc> = DateTime { datetime: naive::MIN_DATETIME, offset: Utc };
+/// The maximum possible `DateTime<Utc>`.
+pub const MAX_DATETIME: DateTime<Utc> = DateTime { datetime: naive::MAX_DATETIME, offset: Utc };
+
 impl<Tz: TimeZone> DateTime<Tz> {
     /// Makes a new `DateTime` with given *UTC* datetime and offset.
     /// The local datetime should be constructed via the `TimeZone` trait.

src/lib.rs

@@ -450,7 +450,7 @@ pub use oldtime::Duration;
 pub use date::{Date, MAX_DATE, MIN_DATE};
 #[cfg(feature = "rustc-serialize")]
 pub use datetime::rustc_serialize::TsSeconds;
-pub use datetime::{DateTime, SecondsFormat};
+pub use datetime::{DateTime, SecondsFormat, MAX_DATETIME, MIN_DATETIME};
 pub use format::{ParseError, ParseResult};
 #[doc(no_inline)]
 pub use naive::{IsoWeek, NaiveDate, NaiveDateTime, NaiveTime};
@@ -511,7 +511,7 @@ pub mod naive {
     #[cfg(feature = "rustc-serialize")]
     #[allow(deprecated)]
     pub use self::datetime::rustc_serialize::TsSeconds;
-    pub use self::datetime::NaiveDateTime;
+    pub use self::datetime::{NaiveDateTime, MAX_DATETIME, MIN_DATETIME};
     pub use self::isoweek::IsoWeek;
     pub use self::time::NaiveTime;
 

src/naive/datetime.rs

@@ -15,6 +15,8 @@ use div::div_mod_floor;
 use format::DelayedFormat;
 use format::{parse, ParseError, ParseResult, Parsed, StrftimeItems};
 use format::{Fixed, Item, Numeric, Pad};
+use naive::date::{MAX_DATE, MIN_DATE};
+use naive::time::{MAX_TIME, MIN_TIME};
 use naive::{IsoWeek, NaiveDate, NaiveTime};
 use {Datelike, Timelike, Weekday};
 
@@ -26,6 +28,11 @@ use {Datelike, Timelike, Weekday};
 /// touching that call when we are already sure that it WILL overflow...
 const MAX_SECS_BITS: usize = 44;
 
+/// The minimum possible `NaiveDateTime`.
+pub const MIN_DATETIME: NaiveDateTime = NaiveDateTime { date: MIN_DATE, time: MIN_TIME };
+/// The maximum possible `NaiveDateTime`.
+pub const MAX_DATETIME: NaiveDateTime = NaiveDateTime { date: MAX_DATE, time: MAX_TIME };
+
 /// ISO 8601 combined date and time without timezone.
 ///
 /// # Example

src/naive/time.rs

@@ -16,6 +16,9 @@ use format::{parse, ParseError, ParseResult, Parsed, StrftimeItems};
 use format::{Fixed, Item, Numeric, Pad};
 use Timelike;
 
+pub const MIN_TIME: NaiveTime = NaiveTime { secs: 0, frac: 0 };
+pub const MAX_TIME: NaiveTime = NaiveTime { secs: 23 * 3600 + 59 * 60 + 59, frac: 999_999_999 };
+
 /// ISO 8601 time without timezone.
 /// Allows for the nanosecond precision and optional leap second representation.
 ///