diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 478d850..57d04af 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -13,8 +13,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '0.7'
-          - '1.0'
+          - '1.6'
           - '1'
 #          - 'nightly'
         os:
diff --git a/Project.toml b/Project.toml
index 5adfb5f..139c97c 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,13 +1,13 @@
 name = "IntervalSets"
 uuid = "8197267c-284f-5f27-9208-e0e47529a953"
-version = "0.5.4"
+version = "0.6.0"
 
 [deps]
 Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 
 [compat]
-julia = "0.7, 1"
+julia = "1.6"
 
 [extras]
 OffsetArrays = "6fe1bfb0-de20-5000-8ca7-80f57d26f881"
diff --git a/src/IntervalSets.jl b/src/IntervalSets.jl
index 051b052..f049519 100644
--- a/src/IntervalSets.jl
+++ b/src/IntervalSets.jl
@@ -62,9 +62,6 @@ isclosedset(d::AbstractInterval) = isleftclosed(d) && isrightclosed(d)
 "Is the interval open?"
 isopenset(d::AbstractInterval) = isleftopen(d) && isrightopen(d)
 
-@deprecate isopen(d) isopenset(d) false
-@deprecate isclosed(d) isclosedset(d)
-
 eltype(::Type{AbstractInterval{T}}) where {T} = T
 @pure eltype(::Type{I}) where {I<:AbstractInterval} = eltype(supertype(I))
 
@@ -134,50 +131,6 @@ in(::Missing, I::TypedEndpointsInterval{:open,:open}) = !isempty(I) && missing
 in(::Missing, I::TypedEndpointsInterval{:closed,:open}) = !isempty(I) && missing
 in(::Missing, I::TypedEndpointsInterval{:open,:closed}) = !isempty(I) && missing
 
-# The code below can be defined as
-# ```
-# function in(a::AbstractInterval, b::AbstractInterval)
-#     Base.depwarn("`in(a::AbstractInterval, b::AbstractInterval)` (equivalently, `a ∈ b`) is deprecated in favor of `issubset(a, b)` (equivalently, `a ⊆ b`). Note that the behavior for empty intervals is also changing.", :in)
-#     return in_deprecation(a, b)
-# end
-# ```
-# but that makes ambiguity definition.
-function in(a::AbstractInterval, b::TypedEndpointsInterval{:closed,:closed})
-    Base.depwarn("`in(a::AbstractInterval, b::AbstractInterval)` (equivalently, `a ∈ b`) is deprecated in favor of `issubset(a, b)` (equivalently, `a ⊆ b`). Note that the behavior for empty intervals is also changing.", :in)
-    return in_deprecation(a, b)
-end
-function in(a::AbstractInterval, b::TypedEndpointsInterval{:open,:open})
-    Base.depwarn("`in(a::AbstractInterval, b::AbstractInterval)` (equivalently, `a ∈ b`) is deprecated in favor of `issubset(a, b)` (equivalently, `a ⊆ b`). Note that the behavior for empty intervals is also changing.", :in)
-    return in_deprecation(a, b)
-end
-function in(a::AbstractInterval, b::TypedEndpointsInterval{:closed,:open})
-    Base.depwarn("`in(a::AbstractInterval, b::AbstractInterval)` (equivalently, `a ∈ b`) is deprecated in favor of `issubset(a, b)` (equivalently, `a ⊆ b`). Note that the behavior for empty intervals is also changing.", :in)
-    return in_deprecation(a, b)
-end
-function in(a::AbstractInterval, b::TypedEndpointsInterval{:open,:closed})
-    Base.depwarn("`in(a::AbstractInterval, b::AbstractInterval)` (equivalently, `a ∈ b`) is deprecated in favor of `issubset(a, b)` (equivalently, `a ⊆ b`). Note that the behavior for empty intervals is also changing.", :in)
-    return in_deprecation(a, b)
-end
-
-in_deprecation(a::AbstractInterval,                         b::TypedEndpointsInterval{:closed,:closed}) =
-    (leftendpoint(a) ≥ leftendpoint(b)) & (rightendpoint(a) ≤ rightendpoint(b))
-in_deprecation(a::TypedEndpointsInterval{:open,:open},      b::TypedEndpointsInterval{:open,:open}    ) =
-    (leftendpoint(a) ≥ leftendpoint(b)) & (rightendpoint(a) ≤ rightendpoint(b))
-in_deprecation(a::TypedEndpointsInterval{:closed,:open},    b::TypedEndpointsInterval{:open,:open}    ) =
-    (leftendpoint(a) > leftendpoint(b)) & (rightendpoint(a) ≤ rightendpoint(b))
-in_deprecation(a::TypedEndpointsInterval{:open,:closed},    b::TypedEndpointsInterval{:open,:open}    ) =
-    (leftendpoint(a) ≥ leftendpoint(b)) & (rightendpoint(a) < rightendpoint(b))
-in_deprecation(a::TypedEndpointsInterval{:closed,:closed},  b::TypedEndpointsInterval{:open,:open}    ) =
-    (leftendpoint(a) > leftendpoint(b)) & (rightendpoint(a) < rightendpoint(b))
-in_deprecation(a::TypedEndpointsInterval{:closed},          b::TypedEndpointsInterval{:open,:closed}  ) =
-    (leftendpoint(a) > leftendpoint(b)) & (rightendpoint(a) ≤ rightendpoint(b))
-in_deprecation(a::TypedEndpointsInterval{:open},            b::TypedEndpointsInterval{:open,:closed}  ) =
-    (leftendpoint(a) ≥ leftendpoint(b)) & (rightendpoint(a) ≤ rightendpoint(b))
-in_deprecation(a::TypedEndpointsInterval{L,:closed}, b::TypedEndpointsInterval{:closed,:open}) where L  =
-    (leftendpoint(a) ≥ leftendpoint(b)) & (rightendpoint(a) < rightendpoint(b))
-in_deprecation(a::TypedEndpointsInterval{L,:open},   b::TypedEndpointsInterval{:closed,:open}) where L  =
-    (leftendpoint(a) ≥ leftendpoint(b)) & (rightendpoint(a) ≤ rightendpoint(b))
-
 isempty(A::TypedEndpointsInterval{:closed,:closed}) = leftendpoint(A) > rightendpoint(A)
 isempty(A::TypedEndpointsInterval) = leftendpoint(A) ≥ rightendpoint(A)
 
@@ -211,9 +164,6 @@ end
 ⊇(A::AbstractInterval, B::AbstractInterval) = issubset(B, A)
 ⊊(A::AbstractInterval, B::AbstractInterval) = (A ≠ B) & (A ⊆ B)
 ⊋(A::AbstractInterval, B::AbstractInterval) = (A ≠ B) & (A ⊇ B)
-if VERSION < v"1.1.0-DEV.123"
-    issubset(x, B::AbstractInterval) = issubset(convert(AbstractInterval, x), B)
-end
 
 const _interval_hash = UInt == UInt64 ? 0x1588c274e0a33ad4 : 0x1e3f7252
 
diff --git a/src/interval.jl b/src/interval.jl
index 13f55b4..c9e8fbe 100644
--- a/src/interval.jl
+++ b/src/interval.jl
@@ -229,7 +229,3 @@ ClosedInterval(i::AbstractUnitRange{I}) where {I<:Integer} = ClosedInterval{I}(m
 
 
 Base.promote_rule(::Type{Interval{L,R,T1}}, ::Type{Interval{L,R,T2}}) where {L,R,T1,T2} = Interval{L,R,promote_type(T1, T2)}
-
-# convert should only work if they represent the same thing.
-@deprecate convert(::Type{R}, i::ClosedInterval{I}) where {R<:AbstractUnitRange,I<:Integer} R(i)
-@deprecate length(i::ClosedInterval) IntervalSets.duration(i)
diff --git a/test/findall.jl b/test/findall.jl
index b2a1df9..e9fbb6c 100644
--- a/test/findall.jl
+++ b/test/findall.jl
@@ -139,13 +139,11 @@ end
                 (-2u"m":0.1u"m":1u"m", -1.05u"m"..1u"km"),
                 (-2u"m":0.1u"m":1u"m", -4u"m"..1u"km"),
                 (-2u"m":0.1u"m":1u"m", -4.05u"m"..1u"km"),
-            ];
-            VERSION >= v"1.4" ? [
                 (Date(2021, 1, 1):Day(1):Date(2021, 3, 1), Date(2020, 1, 11)..Date(2020, 2, 22)),
                 (Date(2021, 1, 1):Day(1):Date(2021, 3, 1), Date(2021, 1, 11)..Date(2021, 2, 22)),
                 (DateTime(2021, 1, 1):Millisecond(10000):DateTime(2021, 3, 1), DateTime(2020, 1, 11)..DateTime(2020, 2, 22)),
                 (DateTime(2021, 1, 1):Millisecond(10000):DateTime(2021, 3, 1), DateTime(2021, 1, 11)..DateTime(2021, 2, 22)),
-            ] : [];
+            ]
         ]
             assert_in_interval(x, interval)
             assert_in_interval(reverse(x), interval)