diff --git a/tools/offline.ml b/tools/offline.ml
index d749813d..8484367c 100644
--- a/tools/offline.ml
+++ b/tools/offline.ml
@@ -19,12 +19,31 @@ module Arg = struct
   include Arg
 
   let timestamp =
-    Arg.Conv.make ~docv:"timestamp argument" ~parser:Timestamp.of_string
-      ~pp:Timestamp.pp ()
+    let parser s =
+      match int_of_string_opt s with
+      | None -> Error "not an int"
+      | Some n -> Time.Timestamp.of_s (Int64.of_int n)
+    in
+    let pp fmt t =
+      match Time.Timestamp.to_s t with
+      | None -> Fmt.pf fmt "never"
+      | Some s -> Fmt.pf fmt "%Ld" s
+    in
+    Arg.Conv.make ~docv:"timestamp argument" ~parser ~pp ()
 
   let relative_time =
-    Arg.Conv.make ~docv:"relative time argument"
-      ~parser:Timestamp.Span.of_string ~pp:Timestamp.Span.pp ()
+    let parser s =
+      match int_of_string_opt s with
+      | None -> Error "not an int"
+      | Some n -> Time.Relative.of_s (Int64.of_int n)
+    in
+    let pp fmt d =
+      let t = Time.Timestamp.of_absolute Time.Absolute.(add zero d) in
+      match Time.Timestamp.to_s t with
+      | None -> Fmt.pf fmt "never"
+      | Some s -> Fmt.pf fmt "%Ld" s
+    in
+    Arg.Conv.make ~docv:"relative time argument" ~parser ~pp ()
 
   let b32 =
     let pp fmt v = Fmt.pf fmt "%s" (B32.encode v) in