diff --git a/Cargo.lock b/Cargo.lock
index 1d443b2..ae0cd4c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -339,7 +339,7 @@ checksum = "329c933548736bc49fd575ee68c89e8be4d260064184389a5b77517cddd99ffb"
 
 [[package]]
 name = "libhaystack"
-version = "1.0.9"
+version = "1.0.10"
 dependencies = [
  "chrono",
  "chrono-tz",
@@ -678,9 +678,9 @@ checksum = "7bd3e3206899af3f8b12af284fafc038cc1dc2b41d1b89dd17297221c5d225de"
 
 [[package]]
 name = "smallvec"
-version = "1.9.0"
+version = "1.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2fd0db749597d91ff862fd1d55ea87f7855a744a8425a64695b6fca237d1dad1"
+checksum = "a507befe795404456341dfab10cef66ead4c041f62b8b11bbb92bffe5d0953e0"
 
 [[package]]
 name = "syn"
diff --git a/Cargo.toml b/Cargo.toml
index 4b539e2..4786c44 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "libhaystack"
-version = "1.0.9"
+version = "1.0.10"
 description = "Rust implementation of the Haystack 4 data types, defs, filter, units, and encodings"
 authors = ["J2 Innovations", "Radu Racariu <radur@j2inn.com>"]
 edition = "2021"
@@ -36,11 +36,14 @@ c-api-zinc = ["zinc"]
 c-api-json = ["json"]
 
 # Lib features
-filter = ["defs",  "zinc-decoding"]
-defs = []
-units = []
-timezone = []
-encoders = ["json", "zinc"]
+value  = ["units", "timezone", "encoders"]
+filter = ["value", "defs",  "zinc-decoding"]
+defs = ["value"]
+units = ["units-db"]
+units-db = []
+timezone = ["timezone-db"]
+timezone-db = []
+encoders = ["value", "json", "zinc"]
 json = ["json-encoding", "json-decoding"]
 json-encoding = []
 json-decoding = []
diff --git a/src/haystack/defs/namespace.rs b/src/haystack/defs/namespace.rs
index aabefa7..3826129 100644
--- a/src/haystack/defs/namespace.rs
+++ b/src/haystack/defs/namespace.rs
@@ -3,6 +3,7 @@
 //! Haystack Def namespace
 
 use dashmap::{mapref::one::Ref as MapReadRef, DashMap};
+use lazy_static::lazy_static;
 use std::collections::{BTreeMap, HashSet};
 
 use super::misc::parse_multi_line_string_to_dicts;
diff --git a/src/haystack/filter/parser.rs b/src/haystack/filter/parser.rs
index bcc146c..6af1485 100644
--- a/src/haystack/filter/parser.rs
+++ b/src/haystack/filter/parser.rs
@@ -7,6 +7,7 @@ use super::nodes::*;
 use super::path::Path;
 use crate::haystack::encoding::zinc::decode::scanner::Scanner;
 use crate::val::{Symbol, Value};
+use lazy_static::lazy_static;
 
 use std::io::{Error, Read};
 
diff --git a/src/haystack/mod.rs b/src/haystack/mod.rs
index 91104e9..b9dd841 100644
--- a/src/haystack/mod.rs
+++ b/src/haystack/mod.rs
@@ -15,6 +15,9 @@ pub mod defs;
 pub mod encoding;
 #[cfg(feature = "filter")]
 pub mod filter;
+#[cfg(feature = "timezone")]
 pub mod timezone;
+#[cfg(feature = "units")]
 pub mod units;
+#[cfg(feature = "value")]
 pub mod val;
diff --git a/src/haystack/timezone/iana.rs b/src/haystack/timezone/iana.rs
index 8f2be3e..8755b84 100644
--- a/src/haystack/timezone/iana.rs
+++ b/src/haystack/timezone/iana.rs
@@ -10,9 +10,9 @@ use chrono_tz::{OffsetName, Tz, UTC};
 use crate::timezone::fixed_timezone;
 
 /// DateTime type that supports timezones
-pub(crate) type DateTimeType = StdDateTime<Tz>;
+pub type DateTimeType = StdDateTime<Tz>;
 
-pub(crate) fn make_date_time(date: StdDateTime<FixedOffset>) -> Result<DateTimeType, String> {
+pub fn make_date_time(date: StdDateTime<FixedOffset>) -> Result<DateTimeType, String> {
     use chrono::LocalResult;
     if let Ok(tz) = find_timezone(&fixed_timezone(&date.offset().to_string())) {
         Ok(match tz.from_local_datetime(&date.naive_local()) {
@@ -37,15 +37,15 @@ pub fn make_date_time_with_tz(
     }
 }
 
-pub(crate) fn utc_now() -> DateTimeType {
+pub fn utc_now() -> DateTimeType {
     Utc::now().with_timezone(&UTC)
 }
 
-pub(crate) fn is_utc(date: &DateTimeType) -> bool {
+pub fn is_utc(date: &DateTimeType) -> bool {
     date.timezone() == UTC
 }
 
-pub(crate) fn timezone_short_name(date: &DateTimeType) -> String {
+pub fn timezone_short_name(date: &DateTimeType) -> String {
     let tz_id = date.offset().tz_id();
 
     tz_id[tz_id.find('/').map_or(0, |v| v + 1)..].to_string()
diff --git a/src/haystack/timezone/mod.rs b/src/haystack/timezone/mod.rs
index 2054882..78e0d0c 100644
--- a/src/haystack/timezone/mod.rs
+++ b/src/haystack/timezone/mod.rs
@@ -6,14 +6,14 @@
 //! provided by [chrono_tz](https://crates.io/crates/chrono-tz), or by just using a fixed offset datetime
 //! by toggling the `timezone` feature.
 
-#[cfg(feature = "timezone")]
+#[cfg(feature = "timezone-db")]
 pub mod iana;
-#[cfg(feature = "timezone")]
-pub(crate) use iana::*;
-#[cfg(not(feature = "timezone"))]
+#[cfg(feature = "timezone-db")]
+pub use iana::*;
+#[cfg(not(feature = "timezone-db"))]
 pub mod utc;
-#[cfg(not(feature = "timezone"))]
-pub(crate) use utc::*;
+#[cfg(not(feature = "timezone-db"))]
+pub use utc::*;
 
 pub(super) fn fixed_timezone(offset: &str) -> String {
     let gmt_offset = offset[2..offset.find(':').unwrap_or(3)].to_string();
diff --git a/src/haystack/timezone/utc.rs b/src/haystack/timezone/utc.rs
index ef0ebc6..042c087 100644
--- a/src/haystack/timezone/utc.rs
+++ b/src/haystack/timezone/utc.rs
@@ -6,35 +6,32 @@ use crate::timezone::fixed_timezone;
 use chrono::{DateTime as StdDateTime, FixedOffset, TimeZone, Utc};
 
 /// DateTime type that works with a fixed offset
-pub(crate) type DateTimeType = StdDateTime<FixedOffset>;
+pub type DateTimeType = StdDateTime<FixedOffset>;
 
-pub(crate) fn make_date_time(value: DateTimeType) -> Result<DateTimeType, String> {
+pub fn make_date_time(value: DateTimeType) -> Result<DateTimeType, String> {
     Ok(value)
 }
 
 /// Constructs an UTC datetime as the timezones are not available
 /// in this configuration.
-pub(crate) fn make_date_time_with_tz(
-    datetime: &DateTimeType,
-    _tz: &str,
-) -> Result<DateTimeType, String> {
+pub fn make_date_time_with_tz(datetime: &DateTimeType, _tz: &str) -> Result<DateTimeType, String> {
     use chrono::Offset;
     Ok(Utc
         .from_utc_datetime(&datetime.naive_utc())
         .with_timezone(&Utc.fix()))
 }
 
-pub(crate) fn utc_now() -> DateTimeType {
+pub fn utc_now() -> DateTimeType {
     Utc::now().into()
 }
 
-pub(crate) fn is_utc(date: &DateTimeType) -> bool {
+pub fn is_utc(date: &DateTimeType) -> bool {
     use chrono::Offset;
 
     &Utc.fix() == date.offset()
 }
 
-pub(crate) fn timezone_short_name(date: &DateTimeType) -> String {
+pub fn timezone_short_name(date: &DateTimeType) -> String {
     let tz_id = fixed_timezone(&date.offset().to_string());
 
     tz_id[tz_id.find('/').map_or(0, |v| v + 1)..].to_string()
diff --git a/src/haystack/units/mod.rs b/src/haystack/units/mod.rs
index b3b527b..91cbe35 100644
--- a/src/haystack/units/mod.rs
+++ b/src/haystack/units/mod.rs
@@ -4,8 +4,9 @@
 
 pub mod unit;
 pub mod unit_dimension;
-#[cfg(feature = "units")]
+#[cfg(feature = "units-db")]
 pub mod units_generated;
+use lazy_static::lazy_static;
 
 pub use unit::Unit;
 pub use unit_dimension::UnitDimensions;
@@ -13,27 +14,23 @@ pub use unit_dimension::UnitDimensions;
 /// Get unit by name, if it is defined in the units database
 #[allow(unused_variables)]
 pub fn get_unit(unit: &str) -> Option<&'static Unit> {
-    #[cfg(feature = "units")]
+    #[cfg(feature = "units-db")]
     {
         return units_generated::UNITS.get(unit).copied();
     }
-    #[cfg(not(feature = "units"))]
+    #[cfg(not(feature = "units-db"))]
     return None;
 }
 
 /// Tries to get the unit by name, if none is found, return a default unit
 pub fn get_unit_or_default(unit: &str) -> &'static Unit {
-    if let Some(unit) = get_unit(unit) {
-        unit
-    } else {
-        &*DEFAULT_UNIT
-    }
+    get_unit(unit).unwrap_or(&*DEFAULT_UNIT)
 }
 
 /// Match units for the dimension
 #[allow(unused_variables)]
 pub fn match_units(dim: UnitDimensions, scale: f64) -> Vec<&'static Unit> {
-    #[cfg(feature = "units")]
+    #[cfg(feature = "units-db")]
     {
         units_generated::UNITS
             .iter()
@@ -46,11 +43,11 @@ pub fn match_units(dim: UnitDimensions, scale: f64) -> Vec<&'static Unit> {
             })
             .collect()
     }
-    #[cfg(not(feature = "units"))]
+    #[cfg(not(feature = "units-db"))]
     return Vec::default();
 }
 
-#[cfg(feature = "units")]
+#[cfg(feature = "units-db")]
 fn approx_eq(a: f64, b: f64) -> bool {
     if a == b {
         return true;
diff --git a/src/haystack/units/unit.rs b/src/haystack/units/unit.rs
index 840ea27..48a9bd3 100644
--- a/src/haystack/units/unit.rs
+++ b/src/haystack/units/unit.rs
@@ -190,6 +190,7 @@ mod test {
         let meters = get_unit("m").expect("Meters");
         let foot = get_unit("ft").expect("Foot");
         assert_eq!(meters.convert_to(1.0, foot).map(|f| f.round()), Ok(3.0));
+        assert_eq!(foot.convert_to(1.0, meters), Ok(0.3048));
 
         let fahrenheit = get_unit("°F").expect("Fahrenheit");
         let celsius = get_unit("°C").expect("Celsius");
diff --git a/src/haystack/units/units_generated.rs b/src/haystack/units/units_generated.rs
index 120c527..f7003e2 100644
--- a/src/haystack/units/units_generated.rs
+++ b/src/haystack/units/units_generated.rs
@@ -3,6 +3,7 @@
 
 #![allow(clippy::approx_constant)]
 use super::{Unit, UnitDimensions};
+use lazy_static::lazy_static;
 use std::collections::HashMap;
 
 // dimensionless
diff --git a/src/lib.rs b/src/lib.rs
index fba8f67..f8740b6 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -14,11 +14,6 @@ pub mod haystack;
 
 pub use haystack::*;
 
-#[cfg(feature = "timezone")]
-extern crate chrono_tz;
-#[macro_use]
-extern crate lazy_static;
-
 #[cfg(target_arch = "wasm32")]
 extern crate web_sys;
 
diff --git a/unit-gen/src/unit_gen.rs b/unit-gen/src/unit_gen.rs
index 3a18176..86237aa 100644
--- a/unit-gen/src/unit_gen.rs
+++ b/unit-gen/src/unit_gen.rs
@@ -57,6 +57,7 @@ fn gen_file_header() -> String {
         "\n",
         "#![allow(clippy::approx_constant)]\n",
         "use super::{Unit, UnitDimensions};\n",
+        "use lazy_static::lazy_static;\n",
         "use std::collections::HashMap;\n"
     )
     .to_string()