diff --git a/crates/re_time_panel/src/time_control_ui.rs b/crates/re_time_panel/src/time_control_ui.rs
index 26272c64a22b..c311d84db555 100644
--- a/crates/re_time_panel/src/time_control_ui.rs
+++ b/crates/re_time_panel/src/time_control_ui.rs
@@ -2,7 +2,7 @@ use egui::NumExt as _;
 
 use re_entity_db::TimesPerTimeline;
 use re_log_types::TimeType;
-use re_ui::UiExt as _;
+use re_ui::{list_item, UiExt as _};
 
 use re_viewer_context::{Looping, PlayState, TimeControl};
 
@@ -39,7 +39,32 @@ impl TimeControlUi {
                             time_control.set_timeline(*timeline);
                         }
                     }
-                });
+                })
+                .response
+                .on_hover_ui(|ui| {
+                    list_item::list_item_scope(ui, "tooltip", |ui| {
+                        ui.markdown_ui(
+                            egui::Id::new("timeline_selector_tooltip"),
+                            r"
+Select timeline.
+
+Each piece of logged data is associated with one or more timelines.
+
+The logging SDK always creates two timelines for you:
+* `log_tick` - a sequence timeline with the sequence number of the log call
+* `log_time` - a temporal timeline with the time of the log call
+
+You can also define your own timelines, e.g. for sensor time or camera frame number.
+"
+                            .trim(),
+                        );
+
+                        ui.re_hyperlink(
+                            "Full documentation",
+                            "https://rerun.io/docs/concepts/timelines",
+                        );
+                    });
+                })
         });
     }