5 files changed, 150 insertions, 5 deletions

diff --git a/src/date.rs b/src/date.rs
index bc2d7dd..ff1805b 100644
--- a/src/date.rs
+++ b/src/date.rs
@@ -1,5 +1,7 @@
 use crate::{Month, Year};
 
+use core::cmp::Ordering;
+
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
 pub struct Date {
 	year: Year,
@@ -52,4 +54,40 @@ impl Date {
 	}
 }
 
+impl PartialOrd for Date {
+	fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+		let year_ordering = self.year.cmp(&other.year);
+		let month_ordering = self.month.cmp(&other.month);
+		let day_ordering = self.day.cmp(&other.day);
+
+		if year_ordering != Ordering::Equal {
+			Some(year_ordering)
+		} else if month_ordering != Ordering::Equal {
+			Some(month_ordering)
+		} else if day_ordering != Ordering::Equal {
+			Some(day_ordering)
+		} else {
+			Some(Ordering::Equal)
+		}
+	}
+}
+
+impl Ord for Date {
+	fn cmp(&self, other: &Self) -> Ordering {
+		let year_ordering = self.year.cmp(&other.year);
+		let month_ordering = self.month.cmp(&other.month);
+		let day_ordering = self.day.cmp(&other.day);
+
+		if year_ordering != Ordering::Equal {
+			year_ordering
+		} else if month_ordering != Ordering::Equal {
+			month_ordering
+		} else if day_ordering != Ordering::Equal {
+			day_ordering
+		} else {
+			Ordering::Equal
+		}
+	}
+}
+
 // TODO addition
diff --git a/src/datetime.rs b/src/datetime.rs
index c739d46..282a56b 100644
--- a/src/datetime.rs
+++ b/src/datetime.rs
@@ -1,4 +1,9 @@
-use crate::{timezone::UtcOffset, Date, Month, Time, TimeZone, Year};
+use crate::{
+	timezone::{Utc, UtcOffset},
+	Date, Month, Time, TimeZone, Year,
+};
+
+use core::{cmp::Ordering, hash::Hash};
 
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
 pub struct NaiveDateTime {
@@ -6,7 +11,7 @@ pub struct NaiveDateTime {
 	time: Time,
 }
 
-#[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
+#[derive(Copy, Clone, Eq, Debug)]
 pub struct DateTime<Tz: TimeZone> {
 	utc_datetime: NaiveDateTime,
 	timezone: Tz,
@@ -14,6 +19,7 @@ pub struct DateTime<Tz: TimeZone> {
 
 impl<Tz: TimeZone> DateTime<Tz> {
 	// TODO unix epoch constant
+	// TODO docs
 
 	pub fn from_utc(utc_datetime: NaiveDateTime, timezone: Tz) -> Self {
 		Self {
@@ -23,7 +29,8 @@ impl<Tz: TimeZone> DateTime<Tz> {
 	}
 
 	pub fn offset(&self) -> UtcOffset {
-		self.timezone.utc_offset(self.utc_datetime)
+		let utc = DateTime::<Utc>::from_utc(self.utc_datetime, Utc);
+		self.timezone.utc_offset(utc)
 	}
 
 	pub fn timezone(&self) -> &Tz {
@@ -87,4 +94,59 @@ impl NaiveDateTime {
 	}
 }
 
+impl PartialOrd for NaiveDateTime {
+	fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+		let date_ordering = self.date.cmp(&other.date);
+		let time_ordering = self.time.cmp(&other.time);
+
+		if date_ordering != Ordering::Equal {
+			Some(date_ordering)
+		} else if time_ordering != Ordering::Equal {
+			Some(time_ordering)
+		} else {
+			Some(Ordering::Equal)
+		}
+	}
+}
+
+impl Ord for NaiveDateTime {
+	fn cmp(&self, other: &Self) -> Ordering {
+		let date_ordering = self.date.cmp(&other.date);
+		let time_ordering = self.time.cmp(&other.time);
+
+		if date_ordering != Ordering::Equal {
+			date_ordering
+		} else if time_ordering != Ordering::Equal {
+			time_ordering
+		} else {
+			Ordering::Equal
+		}
+	}
+}
+
+// TODO think harder about the fact that we don't consider timezone (how will UtcOffset work)
+impl<Tz: TimeZone, Other: TimeZone> PartialEq<DateTime<Other>> for DateTime<Tz> {
+	fn eq(&self, other: &DateTime<Other>) -> bool {
+		self.utc_datetime == other.utc_datetime
+	}
+}
+
+impl<Tz: TimeZone> Hash for DateTime<Tz> {
+	fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+		self.utc_datetime.hash(state)
+	}
+}
+
+impl<Tz: TimeZone, Other: TimeZone> PartialOrd<DateTime<Other>> for DateTime<Tz> {
+	fn partial_cmp(&self, other: &DateTime<Other>) -> Option<Ordering> {
+		self.utc_datetime.partial_cmp(&other.utc_datetime)
+	}
+}
+
+impl<Tz: TimeZone> Ord for DateTime<Tz> {
+	fn cmp(&self, other: &Self) -> Ordering {
+		self.utc_datetime.cmp(&other.utc_datetime)
+	}
+}
+
 // TODO addition
diff --git a/src/month.rs b/src/month.rs
index ebb95e1..4d988b8 100644
--- a/src/month.rs
+++ b/src/month.rs
@@ -7,7 +7,7 @@ use self::Month::*;
 use core::str::FromStr;
 
 /// Months of the year
-#[derive(Copy, Clone, Eq, PartialEq, Hash, Debug, Display)]
+#[derive(Copy, Clone, Eq, PartialEq, Hash, Debug, Display, PartialOrd, Ord)]
 #[repr(u8)]
 pub enum Month {
 	January = 1,
diff --git a/src/time.rs b/src/time.rs
index 94f7cd8..e80e532 100644
--- a/src/time.rs
+++ b/src/time.rs
@@ -1,3 +1,6 @@
+use core::cmp::Ordering;
+use core::fmt::Display;
+
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
 pub struct Time {
 	hour: u8,
@@ -122,4 +125,46 @@ impl Time {
 	}
 }
 
+impl PartialOrd for Time {
+	fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+		let hour_ordering = self.hour.cmp(&other.hour);
+		let minute_ordering = self.minute.cmp(&other.minute);
+		let second_ordering = self.second.cmp(&other.second);
+		let nano_ordering = self.nanosecond.cmp(&other.nanosecond);
+
+		if hour_ordering != Ordering::Equal {
+			Some(hour_ordering)
+		} else if minute_ordering != Ordering::Equal {
+			Some(minute_ordering)
+		} else if second_ordering != Ordering::Equal {
+			Some(second_ordering)
+		} else if nano_ordering != Ordering::Equal {
+			Some(nano_ordering)
+		} else {
+			Some(Ordering::Equal)
+		}
+	}
+}
+
+impl Ord for Time {
+	fn cmp(&self, other: &Self) -> Ordering {
+		let hour_ordering = self.hour.cmp(&other.hour);
+		let minute_ordering = self.minute.cmp(&other.minute);
+		let second_ordering = self.second.cmp(&other.second);
+		let nano_ordering = self.nanosecond.cmp(&other.nanosecond);
+
+		if hour_ordering != Ordering::Equal {
+			hour_ordering
+		} else if minute_ordering != Ordering::Equal {
+			minute_ordering
+		} else if second_ordering != Ordering::Equal {
+			second_ordering
+		} else if nano_ordering != Ordering::Equal {
+			nano_ordering
+		} else {
+			Ordering::Equal
+		}
+	}
+}
+
 // TODO addition
diff --git a/src/weekday.rs b/src/weekday.rs
index b5e3f32..d678b9f 100644
--- a/src/weekday.rs
+++ b/src/weekday.rs
@@ -1,4 +1,4 @@
-use std::str::FromStr;
+use core::str::FromStr;
 
 use derive_more::Display;