diff --git a/src/formatInTimeZone/index.js b/src/formatInTimeZone/index.js
index 0676d84..36ffdfc 100644
--- a/src/formatInTimeZone/index.js
+++ b/src/formatInTimeZone/index.js
@@ -7,8 +7,9 @@ import utcToZonedTime from '../utcToZonedTime'
  * @category Time Zone Helpers
  * @summary Gets the offset in milliseconds between the time zone and Universal Coordinated Time (UTC)
  *
- * @param {Date|Number} date - the date representing the local time / real UTC time
+ * @param {Date|String|Number} date - the date representing the local time / real UTC time
  * @param {String} timeZone - the time zone this date should be formatted for; can be an offset or IANA time zone
+ * @param {String} formatStr - the string of tokens
  * @param {OptionsWithTZ} [options] - the object with options. See [Options]{@link https://date-fns.org/docs/Options}
  * @param {0|1|2} [options.additionalDigits=2] - passed to `toDate`. See [toDate]{@link
  *   https://date-fns.org/docs/toDate}
diff --git a/src/formatInTimeZone/index.js.flow b/src/formatInTimeZone/index.js.flow
index 96104c0..55c4e6e 100644
--- a/src/formatInTimeZone/index.js.flow
+++ b/src/formatInTimeZone/index.js.flow
@@ -16,4 +16,9 @@ type OptionsWithTZ = {
   awareOfUnicodeTokens?: boolean,
 }
 
-declare module.exports: (date: Date | number, timeZone: string, options?: OptionsWithTZ) => string
+declare module.exports: (
+  date: Date | string | number,
+  timeZone: string,
+  formatStr: string,
+  options?: OptionsWithTZ
+) => string
diff --git a/src/fp/formatInTimeZone/index.js b/src/fp/formatInTimeZone/index.js
index 95c0baa..98584d5 100644
--- a/src/fp/formatInTimeZone/index.js
+++ b/src/fp/formatInTimeZone/index.js
@@ -3,6 +3,6 @@
 import fn from '../../formatInTimeZone/index.js'
 import convertToFP from 'date-fns/fp/_lib/convertToFP/index.js'
 
-var formatInTimeZone = convertToFP(fn, 2)
+var formatInTimeZone = convertToFP(fn, 3)
 
 export default formatInTimeZone
diff --git a/src/fp/formatInTimeZone/index.js.flow b/src/fp/formatInTimeZone/index.js.flow
index 7e88a5c..bb3ffeb 100644
--- a/src/fp/formatInTimeZone/index.js.flow
+++ b/src/fp/formatInTimeZone/index.js.flow
@@ -20,4 +20,10 @@ type CurriedFn1<A, R> = <A>(a: A) => R
 
 type CurriedFn2<A, B, R> = <A>(a: A) => CurriedFn1<B, R> | (<A, B>(a: A, b: B) => R)
 
-declare module.exports: CurriedFn2<string, Date | number, string>
+type CurriedFn3<A, B, C, R> = <A>(
+  a: A
+) =>
+  | CurriedFn2<B, C, R>
+  | (<A, B>(a: A, b: B) => CurriedFn1<C, R> | (<A, B, C>(a: A, b: B, c: C) => R))
+
+declare module.exports: CurriedFn3<string, string, Date | string | number, string>
diff --git a/src/fp/formatInTimeZoneWithOptions/index.js b/src/fp/formatInTimeZoneWithOptions/index.js
index eda1d8d..69b1289 100644
--- a/src/fp/formatInTimeZoneWithOptions/index.js
+++ b/src/fp/formatInTimeZoneWithOptions/index.js
@@ -3,6 +3,6 @@
 import fn from '../../formatInTimeZone/index.js'
 import convertToFP from 'date-fns/fp/_lib/convertToFP/index.js'
 
-var formatInTimeZoneWithOptions = convertToFP(fn, 3)
+var formatInTimeZoneWithOptions = convertToFP(fn, 4)
 
 export default formatInTimeZoneWithOptions
diff --git a/src/fp/formatInTimeZoneWithOptions/index.js.flow b/src/fp/formatInTimeZoneWithOptions/index.js.flow
index af469ff..d37f376 100644
--- a/src/fp/formatInTimeZoneWithOptions/index.js.flow
+++ b/src/fp/formatInTimeZoneWithOptions/index.js.flow
@@ -26,4 +26,19 @@ type CurriedFn3<A, B, C, R> = <A>(
   | CurriedFn2<B, C, R>
   | (<A, B>(a: A, b: B) => CurriedFn1<C, R> | (<A, B, C>(a: A, b: B, c: C) => R))
 
-declare module.exports: CurriedFn3<OptionsWithTZ, string, Date | number, string>
+type CurriedFn4<A, B, C, D, R> = <A>(
+  a: A
+) =>
+  | CurriedFn3<B, C, D, R>
+  | (<A, B>(
+      a: A,
+      b: B
+    ) =>
+      | CurriedFn2<C, D, R>
+      | (<A, B, C>(
+          a: A,
+          b: B,
+          c: C
+        ) => CurriedFn1<D, R> | (<A, B, C, D>(a: A, b: B, c: C, d: D) => R)))
+
+declare module.exports: CurriedFn4<OptionsWithTZ, string, string, Date | string | number, string>
diff --git a/src/fp/index.js.flow b/src/fp/index.js.flow
index 43c4771..8900c29 100644
--- a/src/fp/index.js.flow
+++ b/src/fp/index.js.flow
@@ -43,8 +43,14 @@ type CurriedFn4<A, B, C, D, R> = <A>(
 
 declare module.exports: {
   format: CurriedFn2<string, Date | string | number, string>,
-  formatInTimeZone: CurriedFn2<string, Date | number, string>,
-  formatInTimeZoneWithOptions: CurriedFn3<OptionsWithTZ, string, Date | number, string>,
+  formatInTimeZone: CurriedFn3<string, string, Date | string | number, string>,
+  formatInTimeZoneWithOptions: CurriedFn4<
+    OptionsWithTZ,
+    string,
+    string,
+    Date | string | number,
+    string
+  >,
   formatWithOptions: CurriedFn3<OptionsWithTZ, string, Date | string | number, string>,
   getTimezoneOffset: CurriedFn2<Date | number, string, number>,
   toDate: CurriedFn1<Date | string | number, Date>,
diff --git a/src/index.js.flow b/src/index.js.flow
index 11d599e..f678ef3 100644
--- a/src/index.js.flow
+++ b/src/index.js.flow
@@ -19,7 +19,12 @@ type OptionsWithTZ = {
 declare module.exports: {
   format: (date: Date | string | number, format: string, options?: OptionsWithTZ) => string,
 
-  formatInTimeZone: (date: Date | number, timeZone: string, options?: OptionsWithTZ) => string,
+  formatInTimeZone: (
+    date: Date | string | number,
+    timeZone: string,
+    formatStr: string,
+    options?: OptionsWithTZ
+  ) => string,
 
   getTimezoneOffset: (timeZone: string, date?: Date | number) => number,
 
diff --git a/typings.d.ts b/typings.d.ts
index a4602d2..4d05673 100644
--- a/typings.d.ts
+++ b/typings.d.ts
@@ -49,7 +49,12 @@ declare module 'date-fns-tz' {
   function format(date: Date | string | number, format: string, options?: OptionsWithTZ): string
   namespace format {}
 
-  function formatInTimeZone(date: Date | number, timeZone: string, options?: OptionsWithTZ): string
+  function formatInTimeZone(
+    date: Date | string | number,
+    timeZone: string,
+    formatStr: string,
+    options?: OptionsWithTZ
+  ): string
   namespace formatInTimeZone {}
 
   function getTimezoneOffset(timeZone: string, date?: Date | number): number
@@ -171,10 +176,16 @@ declare module 'date-fns-tz/fp' {
   const format: CurriedFn2<string, Date | string | number, string>
   namespace format {}
 
-  const formatInTimeZone: CurriedFn2<string, Date | number, string>
+  const formatInTimeZone: CurriedFn3<string, string, Date | string | number, string>
   namespace formatInTimeZone {}
 
-  const formatInTimeZoneWithOptions: CurriedFn3<OptionsWithTZ, string, Date | number, string>
+  const formatInTimeZoneWithOptions: CurriedFn4<
+    OptionsWithTZ,
+    string,
+    string,
+    Date | string | number,
+    string
+  >
   namespace formatInTimeZoneWithOptions {}
 
   const formatWithOptions: CurriedFn3<OptionsWithTZ, string, Date | string | number, string>
@@ -375,7 +386,12 @@ declare module 'date-fns-tz/esm' {
   function format(date: Date | string | number, format: string, options?: OptionsWithTZ): string
   namespace format {}
 
-  function formatInTimeZone(date: Date | number, timeZone: string, options?: OptionsWithTZ): string
+  function formatInTimeZone(
+    date: Date | string | number,
+    timeZone: string,
+    formatStr: string,
+    options?: OptionsWithTZ
+  ): string
   namespace formatInTimeZone {}
 
   function getTimezoneOffset(timeZone: string, date?: Date | number): number
@@ -497,10 +513,16 @@ declare module 'date-fns-tz/esm/fp' {
   const format: CurriedFn2<string, Date | string | number, string>
   namespace format {}
 
-  const formatInTimeZone: CurriedFn2<string, Date | number, string>
+  const formatInTimeZone: CurriedFn3<string, string, Date | string | number, string>
   namespace formatInTimeZone {}
 
-  const formatInTimeZoneWithOptions: CurriedFn3<OptionsWithTZ, string, Date | number, string>
+  const formatInTimeZoneWithOptions: CurriedFn4<
+    OptionsWithTZ,
+    string,
+    string,
+    Date | string | number,
+    string
+  >
   namespace formatInTimeZoneWithOptions {}
 
   const formatWithOptions: CurriedFn3<OptionsWithTZ, string, Date | string | number, string>