diff --git a/format/date.js b/format/date.js
index aa61d81c..45f6faff 100644
--- a/format/date.js
+++ b/format/date.js
@@ -1,6 +1,5 @@
 import {DateTime, IANAZone} from 'luxon'
-
-const timezones = new WeakMap()
+import {luxonIANAZonesByProfile as timezones} from '../lib/luxon-timezones.js'
 
 // todo: change to `(profile) => (when) => {}`
 const formatDate = (profile, when) => {
diff --git a/format/time.js b/format/time.js
index 975888cc..bd7a31bd 100644
--- a/format/time.js
+++ b/format/time.js
@@ -1,6 +1,5 @@
 import {DateTime, IANAZone} from 'luxon'
-
-const timezones = new WeakMap()
+import {luxonIANAZonesByProfile as timezones} from '../lib/luxon-timezones.js'
 
 // todo: change to `(profile) => (when) => {}`
 const formatTime = (profile, when) => {
diff --git a/lib/luxon-timezones.js b/lib/luxon-timezones.js
new file mode 100644
index 00000000..39027dcd
--- /dev/null
+++ b/lib/luxon-timezones.js
@@ -0,0 +1,6 @@
+// hafas-client profile -> luxon.IANAZone
+const luxonIANAZonesByProfile = new WeakMap()
+
+export {
+	luxonIANAZonesByProfile,
+}
diff --git a/parse/date-time.js b/parse/date-time.js
index 2ee5fa52..4110b212 100644
--- a/parse/date-time.js
+++ b/parse/date-time.js
@@ -1,6 +1,5 @@
 import {DateTime, FixedOffsetZone, IANAZone} from 'luxon'
-
-const timezones = new WeakMap()
+import {luxonIANAZonesByProfile as timezones} from '../lib/luxon-timezones.js'
 
 const parseDateTime = ({profile}, date, time, tzOffset = null, timestamp = false) => {
 	const pDate = [date.substr(-8, 4), date.substr(-4, 2), date.substr(-2, 2)]