diff --git a/game/src/sandbox/mod.rs b/game/src/sandbox/mod.rs
index 471d6050df..47e7f12aec 100644
--- a/game/src/sandbox/mod.rs
+++ b/game/src/sandbox/mod.rs
@@ -869,7 +869,7 @@ fn mouseover_unzoomed_agent_circle(ctx: &mut EventCtx, app: &mut App) {
 }
 
 fn is_daytime(app: &App) -> bool {
-    let hours = app.primary.sim.time().get_parts().0 % 24;
+    let hours = app.primary.sim.time().get_hours() % 24;
     hours >= 6 && hours < 18
 }
 
diff --git a/geom/src/time.rs b/geom/src/time.rs
index 1c6dd38122..f1de19dddb 100644
--- a/geom/src/time.rs
+++ b/geom/src/time.rs
@@ -37,7 +37,7 @@ impl Time {
     }
 
     /// (hours, minutes, seconds, centiseconds)
-    pub fn get_parts(self) -> (usize, usize, usize, usize) {
+    fn get_parts(self) -> (usize, usize, usize, usize) {
         let mut remainder = self.0;
         let hours = (remainder / 3600.0).floor();
         remainder -= hours * 3600.0;
@@ -54,14 +54,9 @@ impl Time {
             centis as usize,
         )
     }
-    /// Rounded up
+    /// Rounded down. 6:59:00 is hour 6.
     pub fn get_hours(self) -> usize {
-        let (hr, min, sec, cs) = self.get_parts();
-        if min > 0 || sec > 0 || cs > 0 {
-            hr + 1
-        } else {
-            hr
-        }
+        self.get_parts().0
     }
 
     pub fn ampm_tostring(self) -> String {
@@ -210,4 +205,17 @@ mod tests {
             Time::parse("07:30:05").unwrap()
         );
     }
+
+    #[test]
+    fn get_hours() {
+        assert_eq!((Time::START_OF_DAY + Duration::hours(6)).get_hours(), 6);
+        assert_eq!(
+            (Time::START_OF_DAY + Duration::hours(6) + Duration::seconds(1.0)).get_hours(),
+            6
+        );
+        assert_eq!(
+            (Time::START_OF_DAY + Duration::hours(6) + Duration::minutes(59)).get_hours(),
+            6
+        );
+    }
 }
diff --git a/sim/src/analytics.rs b/sim/src/analytics.rs
index 9e057eba13..a582811a7d 100644
--- a/sim/src/analytics.rs
+++ b/sim/src/analytics.rs
@@ -535,8 +535,10 @@ impl<X: Ord + Clone> TimeSeriesCount<X> {
             }
         }
 
-        let hour = time.get_parts().0;
-        *self.counts.entry((id, agent_type, hour)).or_insert(0) += count;
+        *self
+            .counts
+            .entry((id, agent_type, time.get_hours()))
+            .or_insert(0) += count;
     }
 
     pub fn total_for(&self, id: X) -> usize {
@@ -561,8 +563,7 @@ impl<X: Ord + Clone> TimeSeriesCount<X> {
     pub fn total_for_by_time(&self, id: X, now: Time) -> usize {
         let mut cnt = 0;
         for agent_type in AgentType::all() {
-            // TODO Off-by-one?
-            for hour in 0..now.get_hours() {
+            for hour in 0..=now.get_hours() {
                 cnt += self
                     .counts
                     .get(&(id.clone(), agent_type, hour))
diff --git a/sim/src/cap.rs b/sim/src/cap.rs
index b88b43a0af..14f4442bc7 100644
--- a/sim/src/cap.rs
+++ b/sim/src/cap.rs
@@ -146,7 +146,7 @@ impl CapSimState {
                     let zone = &mut self.zones[*idx];
 
                     if now - zone.hour_started >= Duration::hours(1) {
-                        zone.hour_started = Time::START_OF_DAY + Duration::hours(now.get_parts().0);
+                        zone.hour_started = Time::START_OF_DAY + Duration::hours(now.get_hours());
                         zone.entered_in_last_hour.clear();
                     }