diff --git a/src/bin/ent/main.rs b/src/bin/ent/main.rs
index 549d16d..e071233 100644
--- a/src/bin/ent/main.rs
+++ b/src/bin/ent/main.rs
@@ -415,116 +415,114 @@ fn handle_command(
         Commands::Assign {
             issue_id,
             new_assignee,
-        } => {
-            let issues = entomologist::database::read_issues_database(issues_database_source)?;
-            let Some(original_issue) = issues.issues.get(issue_id) else {
-                return Err(anyhow::anyhow!("issue {} not found", issue_id));
-            };
-            let old_assignee: String = match &original_issue.assignee {
-                Some(assignee) => assignee.clone(),
-                None => String::from("None"),
-            };
-            println!("issue: {}", issue_id);
-            match new_assignee {
-                Some(new_assignee) => {
-                    let issues_database = entomologist::database::make_issues_database(
-                        issues_database_source,
-                        entomologist::database::IssuesDatabaseAccess::ReadWrite,
-                    )?;
-                    let mut issues =
-                        entomologist::issues::Issues::new_from_dir(&issues_database.dir)?;
-                    let Some(issue) = issues.get_mut_issue(issue_id) else {
-                        return Err(anyhow::anyhow!("issue {} not found", issue_id));
-                    };
-                    println!("assignee: {} -> {}", old_assignee, new_assignee);
-                    issue.set_assignee(new_assignee)?;
+        } => match new_assignee {
+            Some(new_assignee) => {
+                let issues_database = entomologist::database::make_issues_database(
+                    issues_database_source,
+                    entomologist::database::IssuesDatabaseAccess::ReadWrite,
+                )?;
+                let mut issues = entomologist::issues::Issues::new_from_dir(&issues_database.dir)?;
+                let Some(issue) = issues.get_mut_issue(issue_id) else {
+                    return Err(anyhow::anyhow!("issue {} not found", issue_id));
+                };
+                let old_assignee: String = match &issue.assignee {
+                    Some(assignee) => assignee.clone(),
+                    None => String::from("None"),
+                };
+                issue.set_assignee(new_assignee)?;
+                println!("issue: {}", issue_id);
+                println!("assignee: {} -> {}", old_assignee, new_assignee);
+            }
+            None => {
+                let issues = entomologist::database::read_issues_database(issues_database_source)?;
+                let Some(original_issue) = issues.issues.get(issue_id) else {
+                    return Err(anyhow::anyhow!("issue {} not found", issue_id));
+                };
+                let old_assignee: String = match &original_issue.assignee {
+                    Some(assignee) => assignee.clone(),
+                    None => String::from("None"),
+                };
+                println!("issue: {}", issue_id);
+                println!("assignee: {}", old_assignee);
+            }
+        },
+
+        Commands::Tag { issue_id, tag } => match tag {
+            Some(tag) => {
+                // Add or remove tag.
+                if tag.len() == 0 {
+                    return Err(anyhow::anyhow!("invalid zero-length tag"));
                 }
-                None => {
-                    println!("assignee: {}", old_assignee);
+                let issues_database = entomologist::database::make_issues_database(
+                    issues_database_source,
+                    entomologist::database::IssuesDatabaseAccess::ReadWrite,
+                )?;
+                let mut issues = entomologist::issues::Issues::new_from_dir(&issues_database.dir)?;
+                let Some(issue) = issues.get_mut_issue(issue_id) else {
+                    return Err(anyhow::anyhow!("issue {} not found", issue_id));
+                };
+                if tag.chars().nth(0).unwrap() == '-' {
+                    let tag = &tag[1..];
+                    issue.remove_tag(tag)?;
+                } else {
+                    issue.add_tag(tag)?;
                 }
             }
-        }
-
-        Commands::Tag { issue_id, tag } => {
-            let issues = entomologist::database::read_issues_database(issues_database_source)?;
-            let Some(issue) = issues.issues.get(issue_id) else {
-                return Err(anyhow::anyhow!("issue {} not found", issue_id));
-            };
-            match tag {
-                Some(tag) => {
-                    // Add or remove tag.
-                    let issues_database = entomologist::database::make_issues_database(
-                        issues_database_source,
-                        entomologist::database::IssuesDatabaseAccess::ReadWrite,
-                    )?;
-                    let mut issues =
-                        entomologist::issues::Issues::new_from_dir(&issues_database.dir)?;
-                    let Some(issue) = issues.get_mut_issue(issue_id) else {
-                        return Err(anyhow::anyhow!("issue {} not found", issue_id));
-                    };
-                    if tag.len() == 0 {
-                        return Err(anyhow::anyhow!("invalid zero-length tag"));
-                    }
-                    if tag.chars().nth(0).unwrap() == '-' {
-                        let tag = &tag[1..];
-                        issue.remove_tag(tag)?;
-                    } else {
-                        issue.add_tag(tag)?;
-                    }
-                }
-                None => {
-                    // Just list the tags.
-                    match &issue.tags.len() {
-                        0 => println!("no tags"),
-                        _ => {
-                            // Could use `format!(" {:?}", issue.tags)`
-                            // here, but that results in `["tag1", "TAG2",
-                            // "i-am-also-a-tag"]` and i don't want the
-                            // double-quotes around each tag.
-                            for tag in &issue.tags {
-                                println!("{}", tag);
-                            }
+            None => {
+                // Just list the tags.
+                let issues = entomologist::database::read_issues_database(issues_database_source)?;
+                let Some(issue) = issues.issues.get(issue_id) else {
+                    return Err(anyhow::anyhow!("issue {} not found", issue_id));
+                };
+                match &issue.tags.len() {
+                    0 => println!("no tags"),
+                    _ => {
+                        // Could use `format!(" {:?}", issue.tags)`
+                        // here, but that results in `["tag1", "TAG2",
+                        // "i-am-also-a-tag"]` and i don't want the
+                        // double-quotes around each tag.
+                        for tag in &issue.tags {
+                            println!("{}", tag);
                         }
                     }
                 }
             }
-        }
+        },
 
         Commands::DoneTime {
             issue_id,
             done_time,
-        } => {
-            let issues = entomologist::database::read_issues_database(issues_database_source)?;
-            let Some(issue) = issues.issues.get(issue_id) else {
-                return Err(anyhow::anyhow!("issue {} not found", issue_id));
-            };
-            match done_time {
-                Some(done_time) => {
-                    // Add or remove tag.
-                    let issues_database = entomologist::database::make_issues_database(
-                        issues_database_source,
-                        entomologist::database::IssuesDatabaseAccess::ReadWrite,
-                    )?;
-                    let mut issues =
-                        entomologist::issues::Issues::new_from_dir(&issues_database.dir)?;
-                    let Some(issue) = issues.get_mut_issue(issue_id) else {
-                        return Err(anyhow::anyhow!("issue {} not found", issue_id));
-                    };
-                    let done_time = match chrono::DateTime::parse_from_rfc3339(done_time) {
-                        Ok(done_time) => done_time.with_timezone(&chrono::Local),
-                        Err(e) => {
-                            eprintln!("failed to parse done-time from {}", done_time);
-                            return Err(e.into());
-                        }
-                    };
-                    issue.set_done_time(done_time)?;
-                }
-                None => match &issue.done_time {
+        } => match done_time {
+            Some(done_time) => {
+                // Add or remove tag.
+                let issues_database = entomologist::database::make_issues_database(
+                    issues_database_source,
+                    entomologist::database::IssuesDatabaseAccess::ReadWrite,
+                )?;
+                let mut issues = entomologist::issues::Issues::new_from_dir(&issues_database.dir)?;
+                let Some(issue) = issues.get_mut_issue(issue_id) else {
+                    return Err(anyhow::anyhow!("issue {} not found", issue_id));
+                };
+                let done_time = match chrono::DateTime::parse_from_rfc3339(done_time) {
+                    Ok(done_time) => done_time.with_timezone(&chrono::Local),
+                    Err(e) => {
+                        eprintln!("failed to parse done-time from {}", done_time);
+                        return Err(e.into());
+                    }
+                };
+                issue.set_done_time(done_time)?;
+            }
+            None => {
+                let issues = entomologist::database::read_issues_database(issues_database_source)?;
+                let Some(issue) = issues.issues.get(issue_id) else {
+                    return Err(anyhow::anyhow!("issue {} not found", issue_id));
+                };
+                match &issue.done_time {
                     Some(done_time) => println!("done_time: {}", done_time),
                     None => println!("None"),
-                },
-            };
-        }
+                };
+            }
+        },
 
         Commands::Depend {
             issue_id,
diff --git a/src/comment.rs b/src/comment.rs
index 17324b3..e042f63 100644
--- a/src/comment.rs
+++ b/src/comment.rs
@@ -52,8 +52,8 @@ impl Comment {
             return Err(CommentError::CommentParseError);
         };
 
-        let author = crate::git::git_log_oldest_author(comment_dir)?;
-        let creation_time = crate::git::git_log_oldest_timestamp(comment_dir)?;
+        let (author, creation_time) = crate::git::git_log_oldest_author_timestamp(comment_dir)?;
+
         let dir = std::path::PathBuf::from(comment_dir);
 
         Ok(Self {
diff --git a/src/git.rs b/src/git.rs
index 4a50d57..3a03bac 100644
--- a/src/git.rs
+++ b/src/git.rs
@@ -395,6 +395,46 @@ pub fn git_log_oldest_author(path: &std::path::Path) -> Result<String, GitError>
     Ok(String::from(author_last))
 }
 
+pub fn git_log_oldest_author_timestamp(
+    path: &std::path::Path,
+) -> Result<(String, chrono::DateTime<chrono::Local>), GitError> {
+    let mut git_dir = std::path::PathBuf::from(path);
+    git_dir.pop();
+    let result = std::process::Command::new("git")
+        .args([
+            "log",
+            "--pretty=format:%at %an <%ae>",
+            "--",
+            &path
+                .file_name()
+                .ok_or(std::io::Error::from(std::io::ErrorKind::NotFound))?
+                .to_string_lossy(),
+        ])
+        .current_dir(&git_dir)
+        .output()?;
+    if !result.status.success() {
+        println!("stdout: {}", &String::from_utf8_lossy(&result.stdout));
+        println!("stderr: {}", &String::from_utf8_lossy(&result.stderr));
+        return Err(GitError::Oops);
+    }
+
+    let raw_output_str = String::from_utf8_lossy(&result.stdout);
+    let Some(raw_output_last) = raw_output_str.split("\n").last() else {
+        return Err(GitError::Oops);
+    };
+    let Some(index) = raw_output_last.find(' ') else {
+        return Err(GitError::Oops);
+    };
+    let author_str = &raw_output_last[index + 1..];
+    let timestamp_str = &raw_output_last[0..index];
+    let timestamp_i64 = timestamp_str.parse::<i64>()?;
+    let timestamp = chrono::DateTime::from_timestamp(timestamp_i64, 0)
+        .unwrap()
+        .with_timezone(&chrono::Local);
+
+    Ok((String::from(author_str), timestamp))
+}
+
 pub fn create_orphan_branch(branch: &str) -> Result<(), GitError> {
     {
         let tmp_worktree = tempfile::tempdir().unwrap();
diff --git a/src/issue.rs b/src/issue.rs
index aafb4e2..e3bf9d3 100644
--- a/src/issue.rs
+++ b/src/issue.rs
@@ -166,8 +166,7 @@ impl Issue {
             Err(IssueError::IdError)?
         };
 
-        let author = crate::git::git_log_oldest_author(dir)?;
-        let creation_time = crate::git::git_log_oldest_timestamp(dir)?;
+        let (author, creation_time) = crate::git::git_log_oldest_author_timestamp(dir)?;
 
         Ok(Self {
             id,
diff --git a/tools/time-ent b/tools/time-ent
new file mode 100755
index 0000000..366a02c
--- /dev/null
+++ b/tools/time-ent
@@ -0,0 +1,43 @@
+#!/bin/bash
+#
+# * Create a temporary ent issue database branch based on a specific
+#   commit in `entomologist-data`.
+#
+# * Perform some ent operations on this temporary branch and measure
+#   the runtime.
+#
+# * Clean up by deleteting the temporary branch.
+
+set -e
+#set -x
+
+
+# This is a commit in the `entomologist-data` branch that we're somewhat
+# arbitrarily using here to time different `ent` operations.
+TEST_COMMIT=a33f1165d77571d770f1a1021afe4c07360247f0
+
+# This is the branch that we create from the above commit and test our
+# `ent` operations on.  We'll delete this branch when we're done with
+# the tests.
+TEST_BRANCH=$(mktemp --dry-run entomologist-data-XXXXXXXX)
+
+
+function time_ent() {
+    echo timing: ent "$@"
+    time -p ent -b "${TEST_BRANCH}" "$@"
+    echo
+}
+
+
+git branch "${TEST_BRANCH}" "${TEST_COMMIT}"
+
+time_ent tag 7e2a3a59fb6b77403ff1035255367607
+time_ent tag 7e2a3a59fb6b77403ff1035255367607 new-tag
+
+time_ent assign 7e2a3a59fb6b77403ff1035255367607
+time_ent assign 7e2a3a59fb6b77403ff1035255367607 new-user
+
+time_ent done-time 7e2a3a59fb6b77403ff1035255367607
+time_ent done-time 7e2a3a59fb6b77403ff1035255367607 2025-04-01T01:23:45-06:00
+
+git branch -D "${TEST_BRANCH}"