diff --git a/extra/tzdata/checksums b/extra/tzdata/checksums
index 80eb74be..c334617c 100644
--- a/extra/tzdata/checksums
+++ b/extra/tzdata/checksums
@@ -1 +1 @@
-6a1d7b6875313a98136bbf081617c89bdcc16ca41ce093f188a0b53cdde76b86f2
+30f528d38ecd50962098eca70b515a32eb6ff4462eda62f4c9edb40e4559d9c6ce
diff --git a/extra/tzdata/sources b/extra/tzdata/sources
index 1a4847ad..e87526eb 100644
--- a/extra/tzdata/sources
+++ b/extra/tzdata/sources
@@ -1 +1 @@
-https://github.com/eggert/tz/archive/2023b.tar.gz
+https://github.com/eggert/tz/archive/2023c.tar.gz
diff --git a/extra/tzdata/version b/extra/tzdata/version
index ef93f4db..c8dc1d67 100644
--- a/extra/tzdata/version
+++ b/extra/tzdata/version
@@ -1 +1 @@
-2023b 1
+2023c 1