diff --git a/koucha/src/fetch.rs b/koucha/src/fetch.rs
index 62e4505..532b4fe 100644
--- a/koucha/src/fetch.rs
+++ b/koucha/src/fetch.rs
@@ -93,9 +93,9 @@ mod tests {
   use super::*;
   use crate::test_utils::{
     ITEM_TITLE, ITEM_GUID, ITEM_GUID2, ITEM_DESC, ITEM_CONT,
-    CHANNEL_TITLE, CHANNEL_DESC, FEED1
+    CHANNEL_TITLE, CHANNEL_DESC, FEED1,
+    get_datetime
   };
-  use chrono::TimeZone;
 
   fn create_guid(value: String) -> rss::Guid {
     rss::Guid { value, permalink: false }
@@ -140,7 +140,7 @@ mod tests {
 
     let rss_channel = create_channel([rss_item, rss_item2].to_vec());
 
-    let date: DateTime<Utc> = Utc.with_ymd_and_hms(2020,1,1,0,0,0).unwrap();
+    let date: DateTime<Utc> = get_datetime();
 
     let channel = FetchedRSSChannel::parse(rss_channel, date).unwrap();
 
diff --git a/koucha/src/score.rs b/koucha/src/score.rs
index d8ff046..4cdac60 100644
--- a/koucha/src/score.rs
+++ b/koucha/src/score.rs
@@ -54,9 +54,19 @@ pub enum Score {
 
 impl Score {
   pub fn new() -> DecayingScore {
+    Self::new_with_initial(default::INITIAL_SCORE)
+  }
+
+  pub fn new_with_initial(initial_score: i64) -> DecayingScore {
+    Self::new_with_initial_and_time(initial_score, Utc::now())
+  }
+
+  pub fn new_with_initial_and_time(
+    initial: i64, time: DateTime<Utc>
+  ) -> DecayingScore {
     DecayingScore {
-      value: default::INITIAL_SCORE,
-      last_updated: Utc::now(),
+      value: initial,
+      last_updated: time,
     }
   }
 
@@ -68,12 +78,20 @@ impl Score {
   }
 
   pub fn update_score(self, gravity: Gravity) -> Self {
+    self.update_score_at_time(gravity, Utc::now())
+  }
+
+  fn update_score_at_time(self, gravity: Gravity, time: DateTime<Utc>) -> Self {
     match self {
-      Self::Decaying(d) => Score::Decaying(d.update_score(gravity)),
+      Self::Decaying(d) => Score::Decaying(
+        d.apply_gravity_to_time(gravity, time)
+      ),
       Self::Boosted(b) => {
-        let try_unfrozen = b.try_unfreeze();
+        let try_unfrozen = b.try_unfreeze_at_time(time);
         match try_unfrozen {
-          Self::Decaying(s) => Score::Decaying(s.update_score(gravity)),
+          Self::Decaying(s) => Score::Decaying(
+            s.apply_gravity_to_time(gravity, time)
+          ),
           Self::Boosted(b) => Score::Boosted(b),
         }
       }
@@ -110,16 +128,12 @@ impl DecayingScore {
     self.value
   }
 
-  fn update_score(self, gravity: Gravity) -> Self {
-    self.update_score_at_time(gravity, Utc::now())
-  }
-
-  fn update_score_at_time(
+  fn apply_gravity_to_time(
     self, gravity: Gravity, update_time: DateTime<Utc>
   ) -> Self {
     let elapsed_time: TimeDelta = update_time.signed_duration_since(self.last_updated);
     let new_value = if elapsed_time <= TimeDelta::zero() { self.value } else {
-      i64::from(gravity) * (elapsed_time.num_seconds() / SECONDS_IN_A_DAY)
+      self.value + i64::from(gravity) * (elapsed_time.num_seconds() / SECONDS_IN_A_DAY)
     };
     Self {
       last_updated: update_time,
@@ -151,13 +165,9 @@ impl BoostedScore {
     }
   }
 
-  fn try_unfreeze(self) -> Score {
-    self.try_unfreeze_at_time(Utc::now())
-  }
-
   fn try_unfreeze_at_time(self, update_time: DateTime<Utc>) -> Score {
     let boost_end = self.boosted_at + TimeDelta::seconds(default::BOOST_FREEZE_IN_SECONDS);
-    if boost_end > update_time {
+    if boost_end < update_time {
       Score::Decaying(DecayingScore {
         value: self.value,
         last_updated: boost_end,
@@ -167,3 +177,210 @@ impl BoostedScore {
     }
   }
 }
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+  use crate::test_utils::get_datetime;
+
+  #[test]
+  fn gravity_default() {
+    let gravity = Gravity::new(None);
+    assert_eq!(i64::from(gravity), default::GRAVITY);
+  }
+
+  #[test]
+  fn boost_default() {
+    let boost = Boost::new(None);
+    assert_eq!(i64::from(boost), default::BOOST);
+  }
+
+  // "Score" Tests
+
+  #[test]
+  fn parse_decaying() {
+    let ups = UnparsedScore {
+      value: 10,
+      last_updated: get_datetime(),
+      last_boosted: None,
+    };
+
+    ups.parse().get_decaying().unwrap();
+  }
+
+  #[test]
+  fn parse_boosted() {
+    let dt = get_datetime();
+    let ups = UnparsedScore {
+      value: 10,
+      last_updated: dt,
+      last_boosted: Some(dt),
+    };
+
+    ups.parse().get_boosted().unwrap();
+  }
+
+  #[test]
+  fn new() {
+    let score = Score::new();
+    assert_eq!(score.value, default::INITIAL_SCORE);
+  }
+
+  #[test]
+  fn new_with_values() {
+    let dt = get_datetime();
+    let score = Score::new_with_initial_and_time(10, dt);
+    assert_eq!(score.value, 10);
+    assert_eq!(score.last_updated, dt);
+  }
+
+  #[test]
+  fn update_score_stays_decaying() {
+    let dt = get_datetime();
+    let score = Score::Decaying(Score::new_with_initial_and_time(10, dt));
+    let gravity = Gravity::new(None);
+
+    let dt2 = dt + TimeDelta::seconds(SECONDS_IN_A_DAY);
+
+    score.update_score_at_time(gravity, dt2).get_decaying().unwrap();
+  }
+
+  #[test]
+  fn update_score_stays_frozen() {
+    let dt = get_datetime();
+    let score = Score::Boosted(BoostedScore { value: 10, boosted_at: dt });
+    let gravity = Gravity::new(None);
+
+    let dt2 = dt + TimeDelta::seconds(default::BOOST_FREEZE_IN_SECONDS);
+
+    score.update_score_at_time(gravity, dt2).get_boosted().unwrap();
+  }
+
+  #[test]
+  fn update_score_thaws_and_decays() {
+    let dt = get_datetime();
+    let score = Score::Boosted(BoostedScore { value: 10, boosted_at: dt });
+    let gravity = Gravity::new(None);
+
+    let dt2 = dt + TimeDelta::seconds(
+      default::BOOST_FREEZE_IN_SECONDS + SECONDS_IN_A_DAY
+    );
+
+    let updated = score.update_score_at_time(gravity, dt2)
+      .get_decaying().unwrap();
+    assert!(updated.value < 10)
+  }
+
+  #[test]
+  fn get_decaying_success() {
+    let dt = get_datetime();
+    let score = Score::Decaying(Score::new_with_initial_and_time(10, dt));
+
+    score.get_decaying().unwrap();
+  }
+
+  #[test]
+  #[should_panic = "Attempted to get_boosted() of a decaying score"]
+  fn get_boosted_failure() {
+    let dt = get_datetime();
+    let score = Score::Decaying(Score::new_with_initial_and_time(10, dt));
+
+    score.get_boosted().unwrap();
+  }
+
+  #[test]
+  #[should_panic = "Attempted to get_decaying() of a boosted score"]
+  fn get_decaying_failure() {
+    let dt = get_datetime();
+    let boost = Boost::new(None);
+    let score = Score::Boosted(
+      Score::new_with_initial_and_time(10, dt).boost_at_time(boost, dt)
+    );
+
+    score.get_decaying().unwrap();
+  }
+
+  #[test]
+  fn get_boosted_success() {
+    let dt = get_datetime();
+    let boost = Boost::new(None);
+    let score = Score::Boosted(
+      Score::new_with_initial_and_time(10, dt).boost_at_time(boost, dt)
+    );
+
+    score.get_boosted().unwrap();
+  }
+
+  // "DecayingScore" Tests
+
+  #[test]
+  fn apply_gravity_to_future() {
+    let dt = get_datetime();
+    let score = DecayingScore { value: 10, last_updated: dt };
+    let future = dt + TimeDelta::seconds(SECONDS_IN_A_DAY);
+    let gravity = Gravity::new(None);
+
+    let updated = score.apply_gravity_to_time(gravity, future);
+
+    assert_eq!(updated.value, 10 + default::GRAVITY);
+    assert_eq!(updated.last_updated, future);
+  }
+  
+  #[test]
+  fn apply_gravity_to_past() {
+    let dt = get_datetime();
+    let score = DecayingScore { value: 10, last_updated: dt };
+    let past = dt - TimeDelta::seconds(SECONDS_IN_A_DAY);
+    let gravity = Gravity::new(None);
+
+    let updated = score.apply_gravity_to_time(gravity, past);
+
+    assert_eq!(updated.value, 10);
+    assert_eq!(updated.last_updated, past);
+  }
+
+  #[test]
+  fn boost() {
+    let dt = get_datetime();
+    let score = DecayingScore { value: 10, last_updated: dt };
+    let boost = Boost::new(None);
+
+    let boosted = score.boost_at_time(boost, dt);
+    assert_eq!(boosted.value, 10 + default::BOOST);
+    assert_eq!(boosted.boosted_at, dt);
+  }
+
+  // "BoostedScore" tests
+
+  #[test]
+  fn unboost() {
+    let dt = get_datetime();
+    let score = DecayingScore { value: 10, last_updated: dt };
+    let boost = Boost::new(None);
+    let boosted = score.boost_at_time(boost, dt);
+
+    let unboosted = boosted.unboost(boost);
+    assert_eq!(unboosted.value, 10);
+    assert_eq!(unboosted.last_updated, dt);
+  }
+
+  #[test]
+  fn boosted_stays_frozen() {
+    let dt = get_datetime();
+    let score = BoostedScore { value: 10, boosted_at: dt };
+
+    let last_second = dt + TimeDelta::seconds(default::BOOST_FREEZE_IN_SECONDS);
+
+    score.try_unfreeze_at_time(last_second).get_boosted().unwrap();
+  }
+
+  #[test]
+  fn boosted_thaws() {
+    let dt = get_datetime();
+    let score = BoostedScore { value: 10, boosted_at: dt };
+
+    let first_second = dt + TimeDelta::days(default::BOOST_FREEZE_IN_SECONDS+1);
+
+    score.try_unfreeze_at_time(first_second).get_decaying().unwrap();
+  }
+}
diff --git a/koucha/src/test_utils.rs b/koucha/src/test_utils.rs
index 5f2cb9b..870a257 100644
--- a/koucha/src/test_utils.rs
+++ b/koucha/src/test_utils.rs
@@ -11,6 +11,11 @@ use crate::{
   }
 };
 use reqwest::Url;
+use chrono::{
+  Utc,
+  TimeZone,
+  DateTime
+};
 
 pub const FEED1: &str = "https://example.com/feed";
 pub const FEED2: &str = "https://example2.com/feed";
@@ -26,6 +31,11 @@ pub const ITEM_TITLE: &str = "My Item!";
 pub const ITEM_DESC: &str = "My Item's description";
 pub const ITEM_CONT: &str = "The content of my Item";
 
+
+pub fn get_datetime() -> DateTime<Utc> {
+  Utc.with_ymd_and_hms(2020,1,1,0,0,0).unwrap()
+}
+
 pub async fn setup_adapter() -> Adapter {
   AdapterBuilder::new()
     .database_url("sqlite::memory:")