diff --git a/Cargo.toml b/Cargo.toml
index 8995ab151..08a7989e9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,8 +23,8 @@ rust-version = "1.86"
 
 [workspace.dependencies]
 differential-dataflow = { path = "differential-dataflow", default-features = false, version = "0.20.0" }
-timely = { version = "0.27", default-features = false }
-columnar = { version = "0.11", default-features = false }
+timely = { version = "0.28", default-features = false }
+columnar = { version = "0.12", default-features = false }
 #timely = { git = "https://github.com/TimelyDataflow/timely-dataflow" }
 #timely = { path = "../timely-dataflow/timely/", default-features = false }
 
diff --git a/differential-dataflow/src/input.rs b/differential-dataflow/src/input.rs
index 3fd612107..43a4987e8 100644
--- a/differential-dataflow/src/input.rs
+++ b/differential-dataflow/src/input.rs
@@ -258,7 +258,7 @@ impl<T: Timestamp+Clone, D: Data, R: Semigroup+'static> InputSession<T, D, R> {
     /// called, all buffers are flushed and timely dataflow is advised that some logical times are no longer possible.
     pub fn flush(&mut self) {
         self.handle.send_batch(&mut self.buffer);
-        if self.handle.epoch().less_than(&self.time) {
+        if self.handle.time().less_than(&self.time) {
             self.handle.advance_to(self.time.clone());
         }
     }
@@ -269,7 +269,7 @@ impl<T: Timestamp+Clone, D: Data, R: Semigroup+'static> InputSession<T, D, R> {
     /// the session is dropped or flushed. It is not correct to use this time as a basis for a computation's `step_while`
     /// method unless the session has just been flushed.
     pub fn advance_to(&mut self, time: T) {
-        assert!(self.handle.epoch().less_equal(&time));
+        assert!(self.handle.time().less_equal(&time));
         assert!(&self.time.less_equal(&time));
         self.time = time;
     }
diff --git a/differential-dataflow/src/lib.rs b/differential-dataflow/src/lib.rs
index 615aa5ded..b5561cfb2 100644
--- a/differential-dataflow/src/lib.rs
+++ b/differential-dataflow/src/lib.rs
@@ -53,7 +53,7 @@
 //!
 //! ```ignore
 //! loop {
-//!     let time = input.epoch();
+//!     let time = input.time();
 //!     for round in time .. time + 100 {
 //!         input.advance_to(round);
 //!         input.insert((round % 13, round % 7));