diff --git a/src/eval/delta.rs b/src/eval/delta.rs
index 6221a77..423c587 100644
--- a/src/eval/delta.rs
+++ b/src/eval/delta.rs
@@ -7,6 +7,8 @@ use crate::files::primitives::{Span, Spanned, Time, Weekday};
 
 use super::{util, Error, Result};
 
+// TODO Test all these delta steps
+
 /// Like [`commands::DeltaStep`] but includes a new constructor,
 /// [`DeltaStep::Time`].
 #[derive(Debug, Clone, Copy)]
@@ -239,11 +241,27 @@ impl DeltaEval {
     }
 
     fn step_hour(&mut self, span: Span, amount: i32) -> Result<()> {
-        todo!()
+        let time = match self.curr_time {
+            Some(time) => time,
+            None => return Err(self.err_time(span)),
+        };
+
+        let (days, time) = time.add_hours(amount);
+        self.curr += Duration::days(days.into());
+        self.curr_time = Some(time);
+        Ok(())
     }
 
     fn step_minute(&mut self, span: Span, amount: i32) -> Result<()> {
-        todo!()
+        let time = match self.curr_time {
+            Some(time) => time,
+            None => return Err(self.err_time(span)),
+        };
+
+        let (days, time) = time.add_minutes(amount);
+        self.curr += Duration::days(days.into());
+        self.curr_time = Some(time);
+        Ok(())
     }
 
     fn step_weekday(&mut self, amount: i32, weekday: Weekday) {
@@ -261,7 +279,16 @@ impl DeltaEval {
     }
 
     fn step_time(&mut self, span: Span, time: Time) -> Result<()> {
-        todo!()
+        let curr_time = match self.curr_time {
+            Some(time) => time,
+            None => return Err(self.err_time(span)),
+        };
+
+        if time < curr_time {
+            self.curr = self.curr.succ();
+        }
+        self.curr_time = Some(time);
+        Ok(())
     }
 }
 
diff --git a/src/files/primitives.rs b/src/files/primitives.rs
index 8fb34c6..cc93a77 100644
--- a/src/files/primitives.rs
+++ b/src/files/primitives.rs
@@ -1,3 +1,4 @@
+use std::cmp::Ordering;
 use std::fmt;
 
 #[derive(Debug, Clone, Copy)]
@@ -64,6 +65,42 @@ impl Time {
             None
         }
     }
+
+    pub fn add_minutes(&self, amount: i32) -> (i32, Self) {
+        match amount.cmp(&0) {
+            Ordering::Less => {
+                let mut mins = (self.hour as i32) * 60 + (self.min as i32) + amount;
+
+                let days = mins.div_euclid(60 * 24);
+                mins = mins.rem_euclid(60 * 24);
+
+                let hour = mins.div_euclid(60) as u32;
+                let min = mins.rem_euclid(60) as u32;
+                (days, Self::new(hour, min).unwrap())
+            }
+            Ordering::Greater => {
+                let mut mins = (self.hour as i32) * 60 + (self.min as i32) + amount;
+
+                let mut days = mins.div_euclid(60 * 24);
+                mins = mins.rem_euclid(60 * 24);
+
+                // Correct days and minutes so we get 24:00 instead of 00:00
+                if mins == 0 {
+                    days -= 1;
+                    mins = 60 * 24;
+                }
+
+                let hour = mins.div_euclid(60) as u32;
+                let min = mins.rem_euclid(60) as u32;
+                (days, Self::new(hour, min).unwrap())
+            }
+            Ordering::Equal => (0, *self),
+        }
+    }
+
+    pub fn add_hours(&self, amount: i32) -> (i32, Self) {
+        self.add_minutes(amount * 60)
+    }
 }
 
 #[derive(Debug, Clone, Copy)]