diff --git a/Cargo.lock b/Cargo.lock
index 4a6356f8..432f1659 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -202,7 +202,7 @@ dependencies = [
  "arrow-data",
  "arrow-schema",
  "chrono",
- "chrono-tz 0.9.0",
+ "chrono-tz",
  "half",
  "hashbrown 0.14.3",
  "num",
@@ -885,9 +885,9 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
 [[package]]
 name = "chrono"
-version = "0.4.34"
+version = "0.4.38"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5bc015644b92d5890fab7489e49d21f879d5c990186827d42ec511919404f38b"
+checksum = "a21f936df1771bf62b77f047b726c4625ff2e8aa607c01ec06e5a05bd8463401"
 dependencies = [
  "android-tzdata",
  "iana-time-zone",
@@ -898,17 +898,6 @@ dependencies = [
  "windows-targets 0.52.3",
 ]
 
-[[package]]
-name = "chrono-tz"
-version = "0.8.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d59ae0466b83e838b81a54256c39d5d7c20b9d7daa10510a242d9b75abd5936e"
-dependencies = [
- "chrono",
- "chrono-tz-build 0.2.1",
- "phf",
-]
-
 [[package]]
 name = "chrono-tz"
 version = "0.9.0"
@@ -916,19 +905,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "93698b29de5e97ad0ae26447b344c482a7284c737d9ddc5f9e52b74a336671bb"
 dependencies = [
  "chrono",
- "chrono-tz-build 0.3.0",
- "phf",
-]
-
-[[package]]
-name = "chrono-tz-build"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "433e39f13c9a060046954e0592a8d0a4bcb1040125cbf91cb8ee58964cfb350f"
-dependencies = [
- "parse-zoneinfo",
+ "chrono-tz-build",
  "phf",
- "phf_codegen",
+ "uncased",
 ]
 
 [[package]]
@@ -940,6 +919,8 @@ dependencies = [
  "parse-zoneinfo",
  "phf",
  "phf_codegen",
+ "regex",
+ "uncased",
 ]
 
 [[package]]
@@ -3107,6 +3088,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "90fcb95eef784c2ac79119d1dd819e162b5da872ce6f3c3abe1e8ca1c082f72b"
 dependencies = [
  "siphasher",
+ "uncased",
 ]
 
 [[package]]
@@ -4755,6 +4737,15 @@ version = "1.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "42ff0bf0c66b8238c6f3b578df37d0b7848e55df8577b3f74f92a69acceeb825"
 
+[[package]]
+name = "uncased"
+version = "0.9.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e1b88fcfe09e89d3866a5c11019378088af2d24c3fbd4f0543f96b479ec90697"
+dependencies = [
+ "version_check",
+]
+
 [[package]]
 name = "unicase"
 version = "2.7.0"
@@ -4909,7 +4900,7 @@ name = "vegafusion-datafusion-udfs"
 version = "1.6.9"
 dependencies = [
  "chrono",
- "chrono-tz 0.8.6",
+ "chrono-tz",
  "datafusion-functions",
  "datafusion-physical-expr",
  "lazy_static",
@@ -4965,7 +4956,7 @@ dependencies = [
  "base64 0.21.7",
  "bytes",
  "chrono",
- "chrono-tz 0.8.6",
+ "chrono-tz",
  "criterion",
  "datafusion-common",
  "datafusion-expr",
diff --git a/Cargo.toml b/Cargo.toml
index 2e60f7be..20e90548 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -16,7 +16,8 @@ members = [
 [workspace.dependencies]
 arrow = { version = "52.0.0", default-features = false }
 sqlparser = { version = "0.47.0" }
-chrono = { version = "0.4.31", default-features = false }
+chrono = { version = "0.4.35", default-features = false }
+chrono-tz = {version = "0.9.0", features=["case-insensitive", "filter-by-regex"] }
 reqwest = { version = "0.11.22", default-features = false }
 tokio = { version = "1.36.0" }
 pyo3 = { version = "0.21.1" }
diff --git a/vegafusion-datafusion-udfs/Cargo.toml b/vegafusion-datafusion-udfs/Cargo.toml
index db54cbd8..5867c8d8 100644
--- a/vegafusion-datafusion-udfs/Cargo.toml
+++ b/vegafusion-datafusion-udfs/Cargo.toml
@@ -8,12 +8,14 @@ description = "Custom DataFusion UDFs used by VegaFusion"
 [dependencies]
 ordered-float = "3.6.0"
 lazy_static = "^1.4.0"
-chrono-tz = "0.8.1"
 regex = "^1.5.5"
 
 [dependencies.chrono]
 workspace = true
 
+[dependencies.chrono-tz]
+workspace = true
+
 [dependencies.vegafusion-common]
 path = "../vegafusion-common"
 version = "1.6.9"
diff --git a/vegafusion-runtime/Cargo.toml b/vegafusion-runtime/Cargo.toml
index 07f3c3fc..874d9d97 100644
--- a/vegafusion-runtime/Cargo.toml
+++ b/vegafusion-runtime/Cargo.toml
@@ -17,7 +17,6 @@ protobuf-src = [ "vegafusion-core/protobuf-src",]
 regex = "^1.5.5"
 lazy_static = "^1.4.0"
 serde_json = "1.0.91"
-chrono-tz = "0.8.1"
 num-traits = "0.2.15"
 itertools = "0.11.0"
 float-cmp = "0.9.0"
@@ -53,6 +52,9 @@ features = [ "aws",]
 [dependencies.chrono]
 workspace = true
 
+[dependencies.chrono-tz]
+workspace = true
+
 [dependencies.prost]
 workspace = true
 
diff --git a/vegafusion-sql/src/dialect/transforms/date_add_tz.rs b/vegafusion-sql/src/dialect/transforms/date_add_tz.rs
index 24aa868e..dc4b7ff9 100644
--- a/vegafusion-sql/src/dialect/transforms/date_add_tz.rs
+++ b/vegafusion-sql/src/dialect/transforms/date_add_tz.rs
@@ -69,9 +69,7 @@ fn maybe_from_utc(ts_expr: SqlExpr, time_zone: &SqlExpr) -> SqlExpr {
             args: FunctionArguments::List(FunctionArgumentList {
                 args: vec![
                     SqlFunctionArg::Unnamed(SqlFunctionArgExpr::Expr(ts_expr)),
-                    SqlFunctionArg::Unnamed(SqlFunctionArgExpr::Expr(SqlExpr::Value(
-                        SqlValue::SingleQuotedString(time_zone.to_string()),
-                    ))),
+                    SqlFunctionArg::Unnamed(SqlFunctionArgExpr::Expr(time_zone.clone())),
                 ],
                 duplicate_treatment: None,
                 clauses: vec![],
@@ -97,9 +95,7 @@ fn maybe_to_utc(ts_expr: SqlExpr, time_zone: &SqlExpr) -> SqlExpr {
             args: FunctionArguments::List(FunctionArgumentList {
                 args: vec![
                     SqlFunctionArg::Unnamed(SqlFunctionArgExpr::Expr(ts_expr)),
-                    SqlFunctionArg::Unnamed(SqlFunctionArgExpr::Expr(SqlExpr::Value(
-                        SqlValue::SingleQuotedString(time_zone.to_string()),
-                    ))),
+                    SqlFunctionArg::Unnamed(SqlFunctionArgExpr::Expr(time_zone.clone())),
                 ],
                 duplicate_treatment: None,
                 clauses: vec![],