diff --git a/subsys/net/lib/lwm2m/ipso_filling_sensor.c b/subsys/net/lib/lwm2m/ipso_filling_sensor.c
index 478ab0c840d..d85e0d22209 100644
--- a/subsys/net/lib/lwm2m/ipso_filling_sensor.c
+++ b/subsys/net/lib/lwm2m/ipso_filling_sensor.c
@@ -48,8 +48,8 @@ static bool container_full[MAX_INSTANCE_COUNT];
 static double low_threshold[MAX_INSTANCE_COUNT];
 static bool container_empty[MAX_INSTANCE_COUNT];
 static double average_fill_speed[MAX_INSTANCE_COUNT];
-static int64_t forecast_full_date[MAX_INSTANCE_COUNT];
-static int64_t forecast_empty_date[MAX_INSTANCE_COUNT];
+static time_t forecast_full_date[MAX_INSTANCE_COUNT];
+static time_t forecast_empty_date[MAX_INSTANCE_COUNT];
 static bool container_out_of_location[MAX_INSTANCE_COUNT];
 static bool container_out_of_position[MAX_INSTANCE_COUNT];
 
diff --git a/subsys/net/lib/lwm2m/lwm2m_obj_device.c b/subsys/net/lib/lwm2m/lwm2m_obj_device.c
index 16cc7a8ff23..fdad85a7e71 100644
--- a/subsys/net/lib/lwm2m/lwm2m_obj_device.c
+++ b/subsys/net/lib/lwm2m/lwm2m_obj_device.c
@@ -90,8 +90,8 @@ LOG_MODULE_REGISTER(LOG_MODULE_NAME);
 
 /* resource state variables */
 static uint8_t  error_code_list[DEVICE_ERROR_CODE_MAX];
-static int32_t time_temp;
-static uint32_t time_offset;
+static time_t time_temp;
+static time_t time_offset;
 static uint8_t  binding_mode[DEVICE_STRING_SHORT];
 
 /* only 1 instance of device object exists */
@@ -170,7 +170,10 @@ static int current_time_post_write_cb(uint16_t obj_inst_id, uint16_t res_id,
 				      bool last_block, size_t total_size)
 {
 	if (data_len == 4U) {
-		time_offset = *(int32_t *)data - (int32_t)(k_uptime_get() / 1000);
+		time_offset = *(uint32_t *)data - (uint32_t)(k_uptime_get() / 1000);
+		return 0;
+	} else if (data_len == 8U) {
+		time_offset = *(time_t *)data - (time_t)(k_uptime_get() / 1000);
 		return 0;
 	}
 
diff --git a/subsys/net/lib/lwm2m/lwm2m_obj_location.c b/subsys/net/lib/lwm2m/lwm2m_obj_location.c
index 9ab5dacaafd..a7b06ba77b5 100644
--- a/subsys/net/lib/lwm2m/lwm2m_obj_location.c
+++ b/subsys/net/lib/lwm2m/lwm2m_obj_location.c
@@ -42,7 +42,7 @@ static double longitude;
 static double altitude;
 static double radius;
 static double speed;
-static int32_t timestamp;
+static time_t timestamp;
 
 static struct lwm2m_engine_obj location;
 static struct lwm2m_engine_obj_field fields[] = {
diff --git a/tests/net/lib/lwm2m/content_senml_cbor/src/main.c b/tests/net/lib/lwm2m/content_senml_cbor/src/main.c
index 17c7e981271..8fb4aa8b7ca 100644
--- a/tests/net/lib/lwm2m/content_senml_cbor/src/main.c
+++ b/tests/net/lib/lwm2m/content_senml_cbor/src/main.c
@@ -65,7 +65,7 @@ static double test_float;
 static bool test_bool;
 static struct lwm2m_objlnk test_objlnk;
 static uint8_t test_opaque[TEST_OPAQUE_MAX_SIZE];
-static int64_t test_time;
+static time_t test_time;
 
 static struct lwm2m_engine_obj_inst *test_obj_create(uint16_t obj_inst_id)
 {