diff --git a/docs/timestream.rst b/docs/timestream.rst
index dc8405ec7..8b6b8eba6 100644
--- a/docs/timestream.rst
+++ b/docs/timestream.rst
@@ -19,14 +19,10 @@ your fully developed fort appear as energetic as the dwarves in a newly created
 fort, and mature forts are much more fun to play.
 
 Note that whereas your dwarves zip around like you're running at 100 FPS, the
-onscreen FPS counter, if enabled, will still show a lower number. See the
-`Technical details`_ section below if you're interested in what's going on
+vanilla onscreen FPS counter, if enabled, will still show a lower number. See
+the `Technical details`_ section below if you're interested in what's going on
 under the hood.
 
-You can also use this tool to change the in-game calendar speed. Your dwarves
-will be able to get less/more done per season (depending on whether you speed
-up or slow down the calendar).
-
 Usage
 -----
 
@@ -46,12 +42,7 @@ Examples
     which is usually 100).
 
 ``timestream set fps 50``
-    Tweak the simulation so dwarves move at an apparent 50 frames per second.
-
-``timestream set calendar-rate 0.5``
-    Make the days twice as long and allow dwarves to accomplish twice as much
-    per day (requires that your target FPS is set at least 2x higher than the
-    FPS the game is actually running at).
+    Tweak the simulation so it runs at an apparent 50 frames per second.
 
 ``timestream reset``
     Reset settings to defaults: the vanilla FPS cap with no calendar speed
@@ -66,15 +57,6 @@ Settings
     to set the vanilla FPS cap for that. Set a target FPS of -1 to make no
     adjustment at all to the apparent FPS of the game.
 
-:calendar-rate: Set the calendar rate in relation to the target FPS. A calendar
-    rate factor of 1 means time flows "normally" for the units in the game.
-    Values between 0 and 1 slow the calendar relative to the world, allowing
-    units to get more done per day, and values above 1 speed the calendar
-    relative to the world, causing the days to pass quicker and preventing
-    units from getting as much done per day. The actual fps must be below the
-    configured target ``fps`` setting for the ``calendar-rate`` setting to take
-    effect.
-
 Technical details
 -----------------
 
@@ -113,11 +95,12 @@ of their advantage.
 Limitations
 -----------
 
-DF does critial game tasks every 10 ticks that must not be skipped, so
-`timestream` cannot advance more than 9 ticks at a time. This means that, with
-the default target of 100 FPS, the game will start showing signs of slowdown if
-the real FPS drops below about 15. The interface will also become less
-responsive to mouse gestures as the real FPS drops.
+DF does critial game tasks every 10 calendar ticks that must not be skipped, so
+`timestream` cannot advance more than 9 ticks at a time. This puts an upper
+limit on how much `timestream` can help. With the default target of 100 FPS,
+the game will start showing signs of slowdown if the real FPS drops below about
+15. The interface will also become less responsive to mouse gestures as the
+real FPS drops.
 
 Finally, not all aspects of the game are perfectly adjusted. For example,
 armies on world map will move at the same (real-time) rate regardless of
diff --git a/timestream.lua b/timestream.lua
index da82f1673..38af30a8f 100644
--- a/timestream.lua
+++ b/timestream.lua
@@ -22,16 +22,6 @@ local SETTINGS = {
         end,
         default=function() return df.global.init.fps_cap end,
     },
-    {
-        name='calendar-rate',
-        internal_name='calendar_rate',
-        validate=function(arg)
-            local val = tonumber(arg)
-            if not val or val <= 0 then qerror('calendar-rate must be larger than 0') end
-            return val
-        end,
-        default=1.0,
-    },
 }
 
 local function get_default_state()
@@ -74,7 +64,7 @@ local TICK_TRIGGERS = {
 }
 
 -- "owed" ticks we would like to skip at the next opportunity
-local timeskip_deficit, calendar_timeskip_deficit = 0.0, 0.0
+local timeskip_deficit = 0.0
 
 local function get_desired_timeskip(real_fps, desired_fps)
     -- minus 1 to account for the current frame
@@ -265,7 +255,7 @@ end
 local function on_tick()
     local real_fps = math.max(1, dfhack.internal.getUnpausedFps())
     if real_fps >= state.settings.fps then
-        timeskip_deficit, calendar_timeskip_deficit = 0.0, 0.0
+        timeskip_deficit = 0.0
         return
     end
 
@@ -292,12 +282,8 @@ local function on_tick()
     end
     if timeskip <= 0 then return end
 
-    local desired_calendar_timeskip = (timeskip * state.settings.calendar_rate) + calendar_timeskip_deficit
-    local calendar_timeskip = math.max(1, math.floor(desired_calendar_timeskip))
-    calendar_timeskip_deficit = math.max(0, desired_calendar_timeskip - calendar_timeskip)
-
-    df.global.cur_year_tick = df.global.cur_year_tick + calendar_timeskip
-    df.global.cur_year_tick_advmode = df.global.cur_year_tick_advmode + calendar_timeskip*144
+    df.global.cur_year_tick = df.global.cur_year_tick + timeskip
+    df.global.cur_year_tick_advmode = df.global.cur_year_tick_advmode + timeskip*144
 
     adjust_units(timeskip)
     adjust_activities(timeskip)
@@ -307,7 +293,7 @@ end
 -- hook management
 
 local function do_enable()
-    timeskip_deficit, calendar_timeskip_deficit = 0.0, 0.0
+    timeskip_deficit = 0.0
     state.enabled = true
     repeatutil.scheduleEvery(GLOBAL_KEY, 1, 'ticks', on_tick)
 end