From 3632a2ced45f37808df00b8129c0e07b18b7f5a8 Mon Sep 17 00:00:00 2001
From: Gavin Mendel-Gleason <gavin@terminusdb.com>
Date: Thu, 23 Nov 2023 17:48:06 +0100
Subject: [PATCH 1/2] Fix for bug in before epoch dates

---
 src/structure/tfc/datetime.rs | 61 +++++++++++++++++++++++++++++------
 1 file changed, 51 insertions(+), 10 deletions(-)

diff --git a/src/structure/tfc/datetime.rs b/src/structure/tfc/datetime.rs
index 91ee1a47..56615adb 100644
--- a/src/structure/tfc/datetime.rs
+++ b/src/structure/tfc/datetime.rs
@@ -11,10 +11,8 @@ pub fn datetime_to_parts(datetime: &NaiveDateTime) -> (bool, Integer, u32) {
     let mut seconds = Integer::from(datetime.timestamp());
     let is_neg = seconds < 0;
     let mut nanos = datetime.timestamp_subsec_nanos();
-    if is_neg {
-        if nanos != 0 {
-            seconds += 1;
-        }
+    if is_neg && nanos != 0 {
+        seconds += 1;
         nanos = 1_000_000_000 - nanos;
     }
     (is_neg, seconds, nanos)
@@ -31,7 +29,6 @@ pub fn datetime_to_storage(datetime: &NaiveDateTime) -> Vec<u8> {
     } else {
         Some(format!("{nanos:09}"))
     };
-
     integer_and_fraction_to_storage(is_neg, seconds, fraction.as_ref().map(|b| b.as_ref()))
 }
 
@@ -42,11 +39,7 @@ pub fn storage_to_datetime<B: Buf>(bytes: &mut B) -> NaiveDateTime {
         .to_i64()
         .expect("This is a surprisingly large number of seconds!");
     if fraction.is_empty() {
-        if is_pos {
-            NaiveDateTime::from_timestamp_opt(seconds, 0).unwrap()
-        } else {
-            NaiveDateTime::from_timestamp_opt(-seconds, 0).unwrap()
-        }
+        NaiveDateTime::from_timestamp_opt(seconds, 0).unwrap()
     } else {
         let zeros = "0".repeat(9 - fraction.len());
         let fraction = format!("{fraction}{zeros}");
@@ -113,4 +106,52 @@ mod tests {
         let dt_storage = storage_to_datetime(&mut storage.as_slice());
         assert_eq!(dt, dt_storage)
     }
+
+    /*
+    #[test]
+    fn integer_and_fraction() {
+        let vec = integer_and_fraction_to_storage(true, Integer::from(-322704000), None);
+        let (int, is_pos) = storage_to_bigint_and_sign(vec.to_bytes());
+        let fract = decode_fraction(vec);
+    }*/
+
+    #[test]
+    fn no_time_ns() {
+        let year: i32 = 1959;
+        let month: u32 = 10;
+        let day: u32 = 11;
+        let hour: u32 = 0;
+        let minute: u32 = 0;
+        let second: u32 = 0;
+        let nano: u32 = 0;
+        let dt = NaiveDate::from_ymd_opt(year, month, day)
+            .unwrap()
+            .and_hms_nano_opt(hour, minute, second, nano)
+            .unwrap();
+        let result = datetime_to_parts(&dt);
+        assert_eq!((true, Integer::from(-322704000), 0_u32), result);
+        let storage = datetime_to_storage(&dt);
+        let dt_storage = storage_to_datetime(&mut storage.as_slice());
+        assert_eq!(dt, dt_storage)
+    }
+
+    #[test]
+    fn a_bit_of_ns() {
+        let year: i32 = 1959;
+        let month: u32 = 10;
+        let day: u32 = 11;
+        let hour: u32 = 0;
+        let minute: u32 = 0;
+        let second: u32 = 0;
+        let nano: u32 = 3;
+        let dt = NaiveDate::from_ymd_opt(year, month, day)
+            .unwrap()
+            .and_hms_nano_opt(hour, minute, second, nano)
+            .unwrap();
+        let result = datetime_to_parts(&dt);
+        assert_eq!((true, Integer::from(-322703999), 999999997_u32), result);
+        let storage = datetime_to_storage(&dt);
+        let dt_storage = storage_to_datetime(&mut storage.as_slice());
+        assert_eq!(dt, dt_storage)
+    }
 }

From 80f3955c3053cb7ed314714fd2de7f511ee0da18 Mon Sep 17 00:00:00 2001
From: Gavin Mendel-Gleason <gavin@terminusdb.com>
Date: Thu, 23 Nov 2023 20:17:41 +0100
Subject: [PATCH 2/2] Remove commented test

---
 src/structure/tfc/datetime.rs | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/src/structure/tfc/datetime.rs b/src/structure/tfc/datetime.rs
index 56615adb..00994fe6 100644
--- a/src/structure/tfc/datetime.rs
+++ b/src/structure/tfc/datetime.rs
@@ -107,14 +107,6 @@ mod tests {
         assert_eq!(dt, dt_storage)
     }
 
-    /*
-    #[test]
-    fn integer_and_fraction() {
-        let vec = integer_and_fraction_to_storage(true, Integer::from(-322704000), None);
-        let (int, is_pos) = storage_to_bigint_and_sign(vec.to_bytes());
-        let fract = decode_fraction(vec);
-    }*/
-
     #[test]
     fn no_time_ns() {
         let year: i32 = 1959;