diff --git a/src/bin/ent/main.rs b/src/bin/ent/main.rs
index ac55045..a597fd9 100644
--- a/src/bin/ent/main.rs
+++ b/src/bin/ent/main.rs
@@ -41,6 +41,13 @@ enum Commands {
         /// if prefixed with "-".  Example: "tag=bug,-docs" shows issues
         /// that are tagged "bug" and not tagged "docs".  Defaults to
         /// including all tags and excluding none.
+        ///
+        /// "done-time": Time range of issue completion, in the form
+        /// "[START]..[END]".  Includes issues that were marked Done
+        /// between START and END.  START and END are both in RFC 3339
+        /// format, e.g. "YYYY-MM-DDTHH:MM:SS[+-]HH:MM".  If START
+        /// is omitted, defaults to the beginning of time.  If END is
+        /// omitted, defaults to the end of time.
         filter: Vec<String>,
     },
 
@@ -138,6 +145,19 @@ fn handle_command(
                     }
                 }
 
+                if let Some(issue_done_time) = issue.done_time {
+                    if let Some(start_done_time) = filter.start_done_time {
+                        if start_done_time > issue_done_time {
+                            continue;
+                        }
+                    }
+                    if let Some(end_done_time) = filter.end_done_time {
+                        if end_done_time < issue_done_time {
+                            continue;
+                        }
+                    }
+                }
+
                 // This issue passed all the filters, include it in list.
                 uuids_by_state
                     .entry(issue.state.clone())
diff --git a/src/lib.rs b/src/lib.rs
index dbb19e5..b6245b9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -14,6 +14,8 @@ pub enum ParseFilterError {
     ParseError,
     #[error(transparent)]
     IssueParseError(#[from] crate::issue::IssueError),
+    #[error(transparent)]
+    ChronoParseError(#[from] chrono::format::ParseError),
 }
 
 // FIXME: It's easy to imagine a full dsl for filtering issues, for now
@@ -25,6 +27,8 @@ pub struct Filter<'a> {
     pub include_assignees: std::collections::HashSet<&'a str>,
     pub include_tags: std::collections::HashSet<&'a str>,
     pub exclude_tags: std::collections::HashSet<&'a str>,
+    pub start_done_time: Option<chrono::DateTime<chrono::Local>>,
+    pub end_done_time: Option<chrono::DateTime<chrono::Local>>,
 }
 
 impl<'a> Filter<'a> {
@@ -39,6 +43,8 @@ impl<'a> Filter<'a> {
             include_assignees: std::collections::HashSet::<&'a str>::new(),
             include_tags: std::collections::HashSet::<&'a str>::new(),
             exclude_tags: std::collections::HashSet::<&'a str>::new(),
+            start_done_time: None,
+            end_done_time: None,
         }
     }
 
@@ -79,6 +85,27 @@ impl<'a> Filter<'a> {
                 }
             }
 
+            "done-time" => {
+                self.start_done_time = None;
+                self.end_done_time = None;
+                let times: Vec<&str> = tokens[1].split("..").collect();
+                if times.len() > 2 {
+                    return Err(ParseFilterError::ParseError);
+                }
+                if times[0].len() != 0 {
+                    self.start_done_time = Some(
+                        chrono::DateTime::parse_from_rfc3339(times[0])?
+                            .with_timezone(&chrono::Local),
+                    );
+                }
+                if times[1].len() != 0 {
+                    self.end_done_time = Some(
+                        chrono::DateTime::parse_from_rfc3339(times[1])?
+                            .with_timezone(&chrono::Local),
+                    );
+                }
+            }
+
             _ => {
                 println!("unknown filter string '{}'", filter_str);
                 return Err(ParseFilterError::ParseError);