diff --git a/numhask-space.cabal b/numhask-space.cabal
--- a/numhask-space.cabal
+++ b/numhask-space.cabal
@@ -1,6 +1,6 @@
-cabal-version: 3.0
+cabal-version: 2.4
 name: numhask-space
-version: 0.4.0
+version: 0.5.0
 synopsis:
   numerical spaces
 description:
@@ -44,17 +44,17 @@
     OverloadedStrings
     UnicodeSyntax
   build-depends:
-      base >=4.7 && <5
-    , adjunctions >=4.0 && <5
-    , semigroupoids >=5 && <6
-    , distributive >=0.2.2 && <1
-    , lattices >= 2.0.1 && <2.1
-    , time >= 1.8.0.2 && <2
-    , text >= 1.2.3.1 && <2
-    , foldl >= 1.4.5 && <2
-    , containers >= 0.6 && < 0.7
-    , tdigest >= 0.2.1 && < 0.3
-    , protolude >= 0.3.0 && < 0.4.0
+    adjunctions >=4.0 && <5,
+    base >=4.7 && <5,
+    containers >= 0.6 && < 0.7,
+    distributive >=0.2.2 && <1,
+    foldl >= 1.4.5 && <2,
+    lattices >= 2.0.1 && <2.1,
+    protolude >= 0.3.0 && < 0.4.0,
+    semigroupoids >=5 && <6,
+    tdigest >= 0.2.1 && < 0.3,
+    text >= 1.2.3.1 && <2,
+    time >= 1.8.0.2 && <2
   exposed-modules:
     NumHask.Space
     NumHask.Space.Types
@@ -70,10 +70,20 @@
   type: exitcode-stdio-1.0
   main-is: test.hs
   hs-source-dirs:
-      test
-  ghc-options: -Wall -Wcompat -Wincomplete-record-updates -Wincomplete-uni-patterns -Wredundant-constraints
+    test
   build-depends:
-      base >=4.7 && <5
-    , doctest
+    base >=4.7 && <5,
+    doctest >= 0.16 && < 0.18,
+    protolude >= 0.3
   default-language: Haskell2010
-
+  ghc-options:
+    -Wall
+    -Wcompat
+    -Wincomplete-record-updates
+    -Wincomplete-uni-patterns
+    -Wredundant-constraints
+  default-extensions:
+    NegativeLiterals
+    NoImplicitPrelude
+    OverloadedStrings
+    UnicodeSyntax
diff --git a/src/NumHask/Space.hs b/src/NumHask/Space.hs
--- a/src/NumHask/Space.hs
+++ b/src/NumHask/Space.hs
@@ -5,7 +5,6 @@
 -- Mathematics does not define a space, leaving library devs to experiment.
 --
 -- https://en.wikipedia.org/wiki/Space_(mathematics)
---
 module NumHask.Space
   ( -- * Space
     -- $space
@@ -21,11 +20,11 @@
   )
 where
 
+import NumHask.Space.Histogram hiding ()
 import NumHask.Space.Point hiding ()
 import NumHask.Space.Range hiding ()
 import NumHask.Space.Rect hiding ()
 import NumHask.Space.Time hiding ()
-import NumHask.Space.Histogram hiding ()
 import NumHask.Space.Types hiding ()
 
 -- $space
diff --git a/src/NumHask/Space/Histogram.hs b/src/NumHask/Space/Histogram.hs
--- a/src/NumHask/Space/Histogram.hs
+++ b/src/NumHask/Space/Histogram.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE DataKinds #-}
+{-# LANGUAGE NoImplicitPrelude #-}
 {-# OPTIONS_GHC -Wall #-}
 
 -- | A histogram, if you squint, is a series of contiguous ranges, annotated with values.
@@ -17,16 +18,13 @@
 where
 
 import qualified Control.Foldl as L
-import Data.Bool
-import Data.Foldable
-import qualified Data.List
+import qualified Data.List as List
 import qualified Data.Map as Map
-import Data.Maybe
 import Data.TDigest
 import NumHask.Space.Range
 import NumHask.Space.Rect
 import NumHask.Space.Types
-import Prelude
+import Protolude
 
 -- | This Histogram is a list of contiguous boundaries (a boundary being the lower edge of one bucket and the upper edge of another), and a value (usually a count) for each bucket, represented here as a map
 --
@@ -53,7 +51,7 @@
 cutI bs n = go bs 0
   where
     go [] i = i
-    go (x:xs) i = bool i (go xs (i+1)) (n>x)
+    go (x : xs) i = bool i (go xs (i + 1)) (n > x)
 
 -- | Make a histogram using n equally spaced cuts over the entire range of the data
 --
@@ -69,7 +67,7 @@
 -- >>> makeRects IgnoreOvers (regular 4 [0..100])
 -- [Rect 0.0 25.0 0.0 0.25,Rect 25.0 50.0 0.0 0.25,Rect 50.0 75.0 0.0 0.25,Rect 75.0 100.0 0.0 0.25]
 makeRects :: DealOvers -> Histogram -> [Rect Double]
-makeRects o (Histogram cs counts) = Data.List.zipWith4 Rect x z y w'
+makeRects o (Histogram cs counts) = List.zipWith4 Rect x z y w'
   where
     y = repeat 0
     w =
@@ -87,9 +85,9 @@
     x = case o of
       IgnoreOvers -> cs
       IncludeOvers outw ->
-        [Data.List.head cs - outw]
+        [List.head cs - outw]
           <> cs
-          <> [Data.List.last cs + outw]
+          <> [List.last cs + outw]
     z = drop 1 x
 
 -- | approx regular n-quantiles
diff --git a/src/NumHask/Space/Point.hs b/src/NumHask/Space/Point.hs
--- a/src/NumHask/Space/Point.hs
+++ b/src/NumHask/Space/Point.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE NoImplicitPrelude #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# OPTIONS_GHC -Wall #-}
 
@@ -14,14 +15,13 @@
 import Data.Distributive as D
 import Data.Functor.Classes
 import Data.Functor.Rep
-import GHC.Generics (Generic)
+import GHC.Show (show)
 import NumHask.Space.Range
 import NumHask.Space.Types
-import Text.Show
-import Prelude
+import Protolude as P hiding (rotate)
 
 -- $setup
--- 
+-- >>> :set -XNoImplicitPrelude
 
 -- | A 2-dim point of a's
 --
@@ -44,7 +44,7 @@
   deriving (Eq, Generic)
 
 instance (Show a) => Show (Point a) where
-  show (Point a b) = "Point " <> Text.Show.show a <> " " <> Text.Show.show b
+  show (Point a b) = "Point " <> P.show a <> " " <> P.show b
 
 instance Functor Point where
   fmap f (Point a b) = Point (f a) (f b)
@@ -56,7 +56,6 @@
   liftShowsPrec sp _ d (Point a b) = showsBinaryWith sp sp "Point" d a b
 
 instance Applicative Point where
-
   pure a = Point a a
 
   (Point fa fb) <*> Point a b = Point (fa a) (fb b)
@@ -77,19 +76,16 @@
   (Point a0 b0) <> (Point a1 b1) = Point (a0 <> a1) (b0 <> b1)
 
 instance (Semigroup a, Monoid a) => Monoid (Point a) where
-
   mempty = Point mempty mempty
 
   mappend = (<>)
 
 instance (Bounded a) => Bounded (Point a) where
-
   minBound = Point minBound minBound
 
   maxBound = Point maxBound maxBound
 
 instance (Num a) => Num (Point a) where
-
   (Point a0 b0) + (Point a1 b1) = Point (a0 + a1) (b0 + b1)
 
   negate = fmap negate
@@ -103,8 +99,7 @@
   fromInteger x = Point (fromInteger x) (fromInteger x)
 
 instance (Fractional a) => Fractional (Point a) where
-
-  fromRational x = Point (fromRational x) (fromRational x) 
+  fromRational x = Point (fromRational x) (fromRational x)
 
   recip = fmap recip
 
@@ -115,7 +110,6 @@
       getR (Point _ r) = r
 
 instance Representable Point where
-
   type Rep Point = Bool
 
   tabulate f = Point (f False) (f True)
@@ -124,7 +118,6 @@
   index (Point _ r) True = r
 
 instance (Ord a) => Lattice (Point a) where
-
   (\/) (Point x y) (Point x' y') = Point (max x x') (max y y')
 
   (/\) (Point x y) (Point x' y') = Point (min x x') (min y y')
diff --git a/src/NumHask/Space/Range.hs b/src/NumHask/Space/Range.hs
--- a/src/NumHask/Space/Range.hs
+++ b/src/NumHask/Space/Range.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE NoImplicitPrelude #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# OPTIONS_GHC -Wall #-}
 
@@ -10,16 +11,16 @@
 where
 
 import Algebra.Lattice
-import Data.Bool (bool)
+import Control.Category (id)
 import Data.Distributive as D
 import Data.Functor.Apply (Apply (..))
 import Data.Functor.Classes
 import Data.Functor.Rep
 import Data.Semigroup.Foldable (Foldable1 (..))
 import Data.Semigroup.Traversable (Traversable1 (..))
-import GHC.Generics (Generic)
+import GHC.Show (show)
 import NumHask.Space.Types as S
-import Prelude
+import Protolude as P
 
 -- $setup
 
@@ -57,7 +58,7 @@
   deriving (Eq, Generic)
 
 instance (Show a) => Show (Range a) where
-  show (Range a b) = "Range " <> show a <> " " <> show b
+  show (Range a b) = "Range " <> P.show a <> " " <> P.show b
 
 instance Eq1 Range where
   liftEq f (Range a b) (Range c d) = f a c && f b d
@@ -72,7 +73,6 @@
   Range fa fb <.> Range a b = Range (fa a) (fb b)
 
 instance Applicative Range where
-
   pure a = Range a a
 
   (Range fa fb) <*> Range a b = Range (fa a) (fb b)
@@ -95,7 +95,6 @@
       getR (Range _ r) = r
 
 instance Representable Range where
-
   type Rep Range = Bool
 
   tabulate f = Range (f False) (f True)
@@ -104,13 +103,11 @@
   index (Range _ r) True = r
 
 instance (Ord a) => Lattice (Range a) where
-
   (\/) = liftR2 min
 
   (/\) = liftR2 max
 
 instance (Eq a, Ord a) => Space (Range a) where
-
   type Element (Range a) = a
 
   lower (Range l _) = l
@@ -120,7 +117,6 @@
   (>.<) = Range
 
 instance (Ord a, Fractional a) => FieldSpace (Range a) where
-
   type Grid (Range a) = Int
 
   grid o s n = (+ bool 0 (step / 2) (o == MidPos)) <$> posns
@@ -144,7 +140,6 @@
 
 -- | Numeric algebra based on Interval arithmetic
 instance (Num a, Eq a, Ord a) => Num (Range a) where
-
   (Range l u) + (Range l' u') = space1 [l + l', u + u']
 
   negate (Range l u) = negate u ... negate l
@@ -170,7 +165,7 @@
       | err <= 0.75 = 2.0 * step'
       | otherwise = step'
 
--- | a grid with human sensible (rounded) values
+-- | a grid for five-digits per limb species
 --
 -- >>> gridSensible OuterPos False (Range (-12.0) 23.0) 6
 -- [-15.0,-10.0,-5.0,0.0,5.0,10.0,15.0,20.0,25.0]
diff --git a/src/NumHask/Space/Rect.hs b/src/NumHask/Space/Rect.hs
--- a/src/NumHask/Space/Rect.hs
+++ b/src/NumHask/Space/Rect.hs
@@ -2,6 +2,7 @@
 {-# LANGUAGE DeriveTraversable #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE NoImplicitPrelude #-}
 {-# LANGUAGE PatternSynonyms #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# OPTIONS_GHC -Wall #-}
@@ -29,18 +30,16 @@
 where
 
 import Algebra.Lattice
-import Data.Bool (bool)
 import Data.Distributive as D
 import Data.Functor.Compose
 import Data.Functor.Rep
 import Data.List.NonEmpty
-import Data.Semigroup
 import GHC.Exts
-import GHC.Generics (Generic)
+import GHC.Show (show)
 import NumHask.Space.Point
 import NumHask.Space.Range
 import NumHask.Space.Types
-import Prelude
+import Protolude as P hiding (rotate)
 
 -- $setup
 
@@ -79,16 +78,18 @@
 -- | pattern of Rect lowerx upperx lowery uppery
 pattern Rect :: a -> a -> a -> a -> Rect a
 pattern Rect a b c d = Rect' (Compose (Point (Range a b) (Range c d)))
+
 {-# COMPLETE Rect #-}
 
 -- | pattern of Ranges xrange yrange
 pattern Ranges :: Range a -> Range a -> Rect a
 pattern Ranges a b = Rect' (Compose (Point a b))
+
 {-# COMPLETE Ranges #-}
 
 instance (Show a) => Show (Rect a) where
   show (Rect a b c d) =
-    "Rect " <> show a <> " " <> show b <> " " <> show c <> " " <> show d
+    "Rect " <> P.show a <> " " <> P.show b <> " " <> P.show c <> " " <> P.show d
 
 instance Distributive Rect where
   collect f x =
@@ -100,7 +101,6 @@
       getD (Rect _ _ _ d) = d
 
 instance Representable Rect where
-
   type Rep Rect = (Bool, Bool)
 
   tabulate f =
@@ -115,7 +115,6 @@
   (<>) = union
 
 instance (Ord a) => Space (Rect a) where
-
   type Element (Rect a) = Point a
 
   union (Ranges a b) (Ranges c d) = Ranges (a `union` c) (b `union` d)
@@ -142,7 +141,6 @@
   (|<|) s0 s1 = lower s1 `joinLeq` upper s0
 
 instance (Ord a, Fractional a, Num a) => FieldSpace (Rect a) where
-
   type Grid (Rect a) = Point Int
 
   grid o s n = (+ bool 0 (step / 2) (o == MidPos)) <$> posns
@@ -206,7 +204,6 @@
 
 -- | Numeric algebra based on interval arithmetioc for addition and unitRect and projection for multiplication
 instance (Fractional a, Num a, Eq a, Ord a) => Num (Rect a) where
-
   (+) = addRect
 
   negate = fmap negate
diff --git a/src/NumHask/Space/Time.hs b/src/NumHask/Space/Time.hs
--- a/src/NumHask/Space/Time.hs
+++ b/src/NumHask/Space/Time.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE NoImplicitPrelude #-}
 {-# OPTIONS_GHC -Wall #-}
 {-# OPTIONS_GHC -Wno-unused-top-binds #-}
 
@@ -11,16 +12,18 @@
     sensibleTimeGrid,
     PosDiscontinuous (..),
     placedTimeLabelDiscontinuous,
+    placedTimeLabelContinuous,
   )
 where
 
+import Control.Category (id)
 import qualified Control.Foldl as L
-import qualified Data.Text as Text
-import Data.Text (Text)
+import Data.List (nub)
+import Data.String (String)
+import Data.Text (pack, unpack)
 import Data.Time
-import GHC.Generics
 import NumHask.Space.Types
-import Prelude
+import Protolude
 
 -- | parse text as per iso8601
 --
@@ -30,7 +33,7 @@
 -- Just 2017-12-05 00:00:00 UTC
 parseUTCTime :: Text -> Maybe UTCTime
 parseUTCTime =
-  parseTimeM False defaultTimeLocale (iso8601DateFormat Nothing) . Text.unpack
+  parseTimeM False defaultTimeLocale (iso8601DateFormat Nothing) . unpack
 
 -- | a step in time
 data TimeGrain
@@ -203,7 +206,8 @@
 -- | whether to include lower and upper times
 data PosDiscontinuous = PosInnerOnly | PosIncludeBoundaries
 
--- | dates used for time series analysis or attached to charts are often discontinuous, but we want to smooth that reality over and show a continuous range on the axis
+-- | Dates used for time series analysis or attached to charts are often discontinuous, but we want to smooth that reality over and show a continuous range on the axis.
+--
 -- The assumption with getSensibleTimeGrid is that there is a list of discountinuous UTCTimes rather than a continuous range.  Output is a list of index points for the original [UTCTime] and label tuples, and a list of unused list elements.
 --
 -- >>> placedTimeLabelDiscontinuous PosIncludeBoundaries (Just "%d %b") 2 [UTCTime (fromGregorian 2017 12 6) 0, UTCTime (fromGregorian 2017 12 29) 0, UTCTime (fromGregorian 2018 1 31) 0, UTCTime (fromGregorian 2018 3 3) 0]
@@ -220,9 +224,9 @@
     (rem', inds) = L.fold (matchTimes tps') ts
     inds' = laterTimes inds
     fmt = case format of
-      Just f -> Text.unpack f
+      Just f -> unpack f
       Nothing -> autoFormat grain
-    labels = Text.pack . formatTime defaultTimeLocale fmt . snd <$> inds'
+    labels = pack . formatTime defaultTimeLocale fmt . snd <$> inds'
 
 autoFormat :: TimeGrain -> String
 autoFormat (Years x)
@@ -252,6 +256,26 @@
 laterTimes (x : xs) = L.fold (L.Fold step (x, []) (\(x0, x1) -> reverse $ x0 : x1)) xs
   where
     step ((n, a), rs) (na, aa) = if na == n then ((na, aa), rs) else ((na, aa), (n, a) : rs)
+
+-- | A sensible time grid between two dates, projected onto (0,1) with no attempt to get finnicky.
+--
+-- >>> placedTimeLabelContinuous PosIncludeBoundaries (Just "%d %b") 2 (UTCTime (fromGregorian 2017 12 6) 0, UTCTime (fromGregorian 2017 12 29) 0)
+-- [(0.0,"06 Dec"),(0.43478260869565216,"16 Dec"),(0.8695652173913043,"26 Dec"),(1.0,"29 Dec")]
+placedTimeLabelContinuous :: PosDiscontinuous -> Maybe Text -> Int -> (UTCTime, UTCTime) -> [(Double, Text)]
+placedTimeLabelContinuous posd format n (l, u) = zip tpsd labels
+  where
+    (grain, tps) = sensibleTimeGrid InnerPos n (l, u)
+    tps' = case posd of
+      PosInnerOnly -> tps
+      PosIncludeBoundaries -> nub $ [l] <> tps <> [u]
+    fmt = case format of
+      Just f -> unpack f
+      Nothing -> autoFormat grain
+    labels = pack . formatTime defaultTimeLocale fmt <$> tps'
+    l' = minimum tps'
+    u' = maximum tps'
+    r' = toDouble $ diffUTCTime u' l'
+    tpsd = (/ r') . toDouble . flip diffUTCTime l <$> tps'
 
 -- | compute a sensible TimeGrain and list of UTCTimes
 --
diff --git a/src/NumHask/Space/Types.hs b/src/NumHask/Space/Types.hs
--- a/src/NumHask/Space/Types.hs
+++ b/src/NumHask/Space/Types.hs
@@ -28,7 +28,7 @@
 where
 
 import Protolude
-import Data.Foldable
+import Protolude.Partial (foldr1)
 
 -- | Space is a continuous range of numbers that contains elements and has an upper and lower value.
 --
@@ -39,9 +39,7 @@
 -- > norm (norm a) = norm a
 -- > a |>| b == b |<| a
 -- > a |.| singleton a
-
 class Space s where
-
   -- | the underlying element in the space
   type Element s :: Type
 
@@ -57,7 +55,6 @@
 
   -- | the intersection of two spaces
   intersection :: s -> s -> s
-
   default intersection :: (Ord (Element s)) => s -> s -> s
   intersection a b = l >.< u
     where
@@ -66,7 +63,6 @@
 
   -- | the union of two spaces
   union :: s -> s -> s
-
   default union :: (Ord (Element s)) => s -> s -> s
   union a b = l >.< u
     where
@@ -74,6 +70,7 @@
       u = upper a `max` upper b
 
   -- | Normalise a space so that
+  --
   -- > lower a \/ upper a == lower a
   -- > lower a /\ upper a == upper a
   norm :: s -> s
@@ -83,7 +80,6 @@
   infix 3 ...
 
   (...) :: Element s -> Element s -> s
-
   default (...) :: (Ord (Element s)) => Element s -> Element s -> s
   (...) a b = (a `min` b) >.< (a `max` b)
 
@@ -96,7 +92,6 @@
   infixl 7 |.|
 
   (|.|) :: Element s -> s -> Bool
-
   default (|.|) :: (Ord (Element s)) => Element s -> s -> Bool
   (|.|) a s = (a >= lower s) && (upper s >= a)
 
@@ -104,7 +99,6 @@
   infixl 7 |>|
 
   (|>|) :: s -> s -> Bool
-
   default (|>|) :: (Ord (Element s)) => s -> s -> Bool
   (|>|) s0 s1 =
     lower s0 >= upper s1
@@ -113,7 +107,6 @@
   infixl 7 |<|
 
   (|<|) :: s -> s -> Bool
-
   default (|<|) :: (Ord (Element s)) => s -> s -> Bool
   (|<|) s0 s1 =
     lower s1 <= upper s0
@@ -162,7 +155,6 @@
 -- > space1 (grid OuterPos s g) == s
 -- > getUnion (sconcat (Union <$> (gridSpace s g))) == s
 class (Space s, Num (Element s)) => FieldSpace s where
-
   type Grid s :: Type
 
   -- | create equally-spaced elements across a space
@@ -172,17 +164,18 @@
   gridSpace :: s -> Grid s -> [s]
 
 -- | Pos suggests where points should be placed in forming a grid across a field space.
-data Pos =
-  -- | include boundaries
-  OuterPos |
-  -- | don't include boundaries
-  InnerPos |
-  -- | include the lower boundary
-  LowerPos |
-  -- | include the upper boundary
-  UpperPos |
-  -- | use the mid-point of the space
-  MidPos deriving (Show, Eq)
+data Pos
+  = -- | include boundaries
+    OuterPos
+  | -- | don't include boundaries
+    InnerPos
+  | -- | include the lower boundary
+    LowerPos
+  | -- | include the upper boundary
+    UpperPos
+  | -- | use the mid-point of the space
+    MidPos
+  deriving (Show, Eq)
 
 -- | middle element of the space
 mid :: (Space s, Fractional (Element s)) => s -> Element s
@@ -192,12 +185,14 @@
 --
 -- > project o n (lower o) = lower n
 -- > project o n (upper o) = upper n
+-- > project o n (mid o) = mid n
 -- > project a a x = x
 project :: (Space s, Fractional (Element s)) => s -> s -> Element s -> Element s
 project s0 s1 p =
   ((p - lower s0) / (upper s0 - lower s0)) * (upper s1 - lower s1) + lower s1
 
 -- | the containing space of a non-empty Traversable
+--
 -- > all $ space1 a `contains` <$> a
 space1 :: (Space s, Traversable f) => f (Element s) -> s
 space1 = foldr1 union . fmap singleton
diff --git a/test/test.hs b/test/test.hs
--- a/test/test.hs
+++ b/test/test.hs
@@ -2,8 +2,8 @@
 
 module Main where
 
+import Protolude
 import Test.DocTest
-import Prelude
 
 main :: IO ()
 main =