diff --git a/Tests/ConfidenceProviderTests/ConfidenceTypeMapperTest.swift b/Tests/ConfidenceProviderTests/ConfidenceTypeMapperTest.swift
index 35988d71..3964cff7 100644
--- a/Tests/ConfidenceProviderTests/ConfidenceTypeMapperTest.swift
+++ b/Tests/ConfidenceProviderTests/ConfidenceTypeMapperTest.swift
@@ -64,6 +64,7 @@ class ValueConverterTest: XCTestCase {
 
     func testContextConversionWithLists() throws {
         let formatter = DateFormatter()
+        formatter.locale = Locale(identifier: "en_US_POSIX")
         formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
         let date1 = try XCTUnwrap(formatter.date(from: "2022-01-01 12:00:00"))
         let date2 = try XCTUnwrap(formatter.date(from: "2022-01-02 12:00:00"))
@@ -112,6 +113,7 @@ class ValueConverterTest: XCTestCase {
 
     func testValueConversion() throws {
         let formatter = DateFormatter()
+        formatter.locale = Locale(identifier: "en_US_POSIX")
         formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
         let date = try XCTUnwrap(formatter.date(from: "2022-01-01 12:00:00"))
 
diff --git a/Tests/ConfidenceTests/ConfidenceIntegrationTest.swift b/Tests/ConfidenceTests/ConfidenceIntegrationTest.swift
index 32732c10..c3f2c096 100644
--- a/Tests/ConfidenceTests/ConfidenceIntegrationTest.swift
+++ b/Tests/ConfidenceTests/ConfidenceIntegrationTest.swift
@@ -178,6 +178,7 @@ class ConfidenceIntegrationTests: XCTestCase {
 
     private func convertStringToDate(_ dateString: String) -> Date? {
         let dateFormatter = DateFormatter()
+        dateFormatter.locale = Locale(identifier: "en_US_POSIX")
         dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZ"
         return dateFormatter.date(from: dateString)
     }
diff --git a/Tests/ConfidenceTests/ConfidenceValueTests.swift b/Tests/ConfidenceTests/ConfidenceValueTests.swift
index 902f50a2..37c8535c 100644
--- a/Tests/ConfidenceTests/ConfidenceValueTests.swift
+++ b/Tests/ConfidenceTests/ConfidenceValueTests.swift
@@ -29,6 +29,7 @@ final class ConfidenceConfidenceValueTests: XCTestCase {
 
     func testStringShouldConvertToDate() throws {
         let formatter = DateFormatter()
+        formatter.locale = Locale(identifier: "en_US_POSIX")
         formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
         let date = try XCTUnwrap(formatter.date(from: "2022-01-01 12:00:00"))
         let value = ConfidenceValue(timestamp: date)
@@ -43,6 +44,7 @@ final class ConfidenceConfidenceValueTests: XCTestCase {
 
     func testListShouldConvertToList() throws {
         let formatter = DateFormatter()
+        formatter.locale = Locale(identifier: "en_US_POSIX")
         formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
         formatter.timeZone = TimeZone(abbreviation: "UTC")
         let date1 = try XCTUnwrap(formatter.date(from: "2022-01-01 12:00:00"))
@@ -106,6 +108,7 @@ final class ConfidenceConfidenceValueTests: XCTestCase {
 
     func testEncodeDecode() throws {
         let formatter = DateFormatter()
+        formatter.locale = Locale(identifier: "en_US_POSIX")
         formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
         formatter.timeZone = TimeZone(abbreviation: "EDT") // Verify TimeZone conversion
         let date = try XCTUnwrap(formatter.date(from: "2024-04-05 16:00:00"))
diff --git a/Tests/ConfidenceTests/TypeMapperTests.swift b/Tests/ConfidenceTests/TypeMapperTests.swift
index ac5168f7..88c50f3a 100644
--- a/Tests/ConfidenceTests/TypeMapperTests.swift
+++ b/Tests/ConfidenceTests/TypeMapperTests.swift
@@ -38,6 +38,7 @@ class TypeMapperTests: XCTestCase {
 
     func testConfidenceToNetwork() throws {
         let formatter = DateFormatter()
+        formatter.locale = Locale(identifier: "en_US_POSIX")
         formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
         formatter.timeZone = TimeZone.init(identifier: "UTC+01")
         let date = try XCTUnwrap(formatter.date(from: "2022-01-01 12:00:00"))