diff --git a/.vscode/cspell.dictionaries/workspace.wordlist.txt b/.vscode/cspell.dictionaries/workspace.wordlist.txt
index d6e91dca5bf..6d6533bcf5c 100644
--- a/.vscode/cspell.dictionaries/workspace.wordlist.txt
+++ b/.vscode/cspell.dictionaries/workspace.wordlist.txt
@@ -20,6 +20,7 @@ exacl
 filetime
 formatteriteminfo
 fsext
+fundu
 getopts
 getrandom
 globset
diff --git a/Cargo.lock b/Cargo.lock
index 4d53a4c2ee0..98b5cb97325 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -880,9 +880,9 @@ dependencies = [
 
 [[package]]
 name = "fundu"
-version = "0.3.0"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "925250bc259498d4008ee072bf16586083ab2c491aa4b06b3c4d0a6556cebd74"
+checksum = "da58c38fe7b706cead98429d8a8535261addbe55fd531c7d7c7d770346464010"
 
 [[package]]
 name = "futures"
@@ -3041,6 +3041,7 @@ name = "uu_sleep"
 version = "0.0.17"
 dependencies = [
  "clap",
+ "fundu",
  "uucore",
 ]
 
diff --git a/Cargo.toml b/Cargo.toml
index be545c8604e..1fe04f34c5b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -282,7 +282,7 @@ filetime = "0.2"
 fnv = "1.0.7"
 fs_extra = "1.1.0"
 fts-sys = "0.2"
-fundu = "0.3.0"
+fundu = "0.4.2"
 gcd = "2.2"
 glob = "0.3.0"
 half = "2.1"
diff --git a/src/uu/sleep/Cargo.toml b/src/uu/sleep/Cargo.toml
index 048f551c130..aa4bf0664ba 100644
--- a/src/uu/sleep/Cargo.toml
+++ b/src/uu/sleep/Cargo.toml
@@ -16,6 +16,7 @@ path = "src/sleep.rs"
 
 [dependencies]
 clap = { workspace=true }
+fundu = { workspace=true }
 uucore = { workspace=true }
 
 [[bin]]
diff --git a/src/uu/sleep/src/sleep.rs b/src/uu/sleep/src/sleep.rs
index 4751d89b2f2..009986095f6 100644
--- a/src/uu/sleep/src/sleep.rs
+++ b/src/uu/sleep/src/sleep.rs
@@ -14,6 +14,7 @@ use uucore::{
 };
 
 use clap::{crate_version, Arg, ArgAction, Command};
+use fundu::{self, DurationParser, ParseError};
 
 static ABOUT: &str = help_about!("sleep.md");
 const USAGE: &str = help_usage!("sleep.md");
@@ -61,14 +62,34 @@ pub fn uu_app() -> Command {
 
 fn sleep(args: &[&str]) -> UResult<()> {
     let mut arg_error = false;
+
+    use fundu::TimeUnit::*;
+    let parser = DurationParser::with_time_units(&[Second, Minute, Hour, Day]);
+
     let sleep_dur = args
         .iter()
-        .filter_map(|input| {
-            uucore::parse_time::from_str(input.trim()).ok().or_else(|| {
+        .filter_map(|input| match parser.parse(input.trim()) {
+            Ok(duration) => Some(duration),
+            Err(error) => {
                 arg_error = true;
-                show_error!("invalid time interval '{input}'");
+
+                let reason = match error {
+                    ParseError::Empty if input.is_empty() => "Input was empty".to_string(),
+                    ParseError::Empty => "Found only whitespace in input".to_string(),
+                    ParseError::Syntax(pos, description)
+                    | ParseError::TimeUnit(pos, description) => {
+                        format!("{description} at position {}", pos.saturating_add(1))
+                    }
+                    ParseError::NegativeExponentOverflow | ParseError::PositiveExponentOverflow => {
+                        "Exponent was out of bounds".to_string()
+                    }
+                    ParseError::NegativeNumber => "Number was negative".to_string(),
+                    error => error.to_string(),
+                };
+                show_error!("invalid time interval '{input}': {reason}");
+
                 None
-            })
+            }
         })
         .fold(Duration::ZERO, |acc, n| acc.saturating_add(n));
 
diff --git a/tests/by-util/test_sleep.rs b/tests/by-util/test_sleep.rs
index c525cc0d2cc..8bb4b11ea4f 100644
--- a/tests/by-util/test_sleep.rs
+++ b/tests/by-util/test_sleep.rs
@@ -10,11 +10,11 @@ fn test_invalid_time_interval() {
     new_ucmd!()
         .arg("xyz")
         .fails()
-        .usage_error("invalid time interval 'xyz'");
+        .usage_error("invalid time interval 'xyz': Invalid character: 'x' at position 1");
     new_ucmd!()
         .args(&["--", "-1"])
         .fails()
-        .usage_error("invalid time interval '-1'");
+        .usage_error("invalid time interval '-1': Number was negative");
 }
 
 #[test]
@@ -204,14 +204,16 @@ fn test_sleep_when_input_has_only_whitespace_then_error(#[case] input: &str) {
         .arg(input)
         .timeout(Duration::from_secs(10))
         .fails()
-        .usage_error(format!("invalid time interval '{input}'"));
+        .usage_error(format!(
+            "invalid time interval '{input}': Found only whitespace in input"
+        ));
 }
 
 #[test]
 fn test_sleep_when_multiple_input_some_with_error_then_shows_all_errors() {
-    let expected = "invalid time interval 'abc'\n\
-        sleep: invalid time interval '1years'\n\
-        sleep: invalid time interval ' '";
+    let expected = "invalid time interval 'abc': Invalid character: 'a' at position 1\n\
+        sleep: invalid time interval '1years': Invalid time unit: 'years' at position 2\n\
+        sleep: invalid time interval ' ': Found only whitespace in input";
 
     // Even if one of the arguments is valid, but the rest isn't, we should still fail and exit early.
     // So, the timeout of 10 seconds ensures we haven't executed `thread::sleep` with the only valid
@@ -228,5 +230,5 @@ fn test_negative_interval() {
     new_ucmd!()
         .args(&["--", "-1"])
         .fails()
-        .usage_error("invalid time interval '-1'");
+        .usage_error("invalid time interval '-1': Number was negative");
 }
diff --git a/tests/by-util/test_tail.rs b/tests/by-util/test_tail.rs
index eb18e858f74..93ca1046d47 100644
--- a/tests/by-util/test_tail.rs
+++ b/tests/by-util/test_tail.rs
@@ -4459,7 +4459,7 @@ fn test_follow_when_files_are_pointing_to_same_relative_file_and_file_stays_same
 }
 
 #[rstest]
-#[case::exponent_exceed_float_max("1.0e2048")]
+#[case::exponent_exceed_float_max("1.0e100000")]
 #[case::underscore_delimiter("1_000")]
 #[case::only_point(".")]
 #[case::space_in_primes("' '")]