diff --git a/PostgreSQL/OMOP CDM ddl - PostgreSQL.sql b/PostgreSQL/OMOP CDM ddl - PostgreSQL.sql
index 9f40559..3d4e292 100644
--- a/PostgreSQL/OMOP CDM ddl - PostgreSQL.sql	
+++ b/PostgreSQL/OMOP CDM ddl - PostgreSQL.sql	
@@ -229,7 +229,7 @@ CREATE TABLE person
      year_of_birth					INTEGER		NOT NULL , 
      month_of_birth					INTEGER		NULL, 
      day_of_birth					INTEGER		NULL, 
-	 time_of_birth					VARCHAR(10)	NULL,
+	 datetime_of_birth					TIMESTAMP 	NULL,
      race_concept_id				INTEGER		NOT NULL, 
      ethnicity_concept_id			INTEGER		NOT NULL, 
      location_id					INTEGER		NULL, 
@@ -254,7 +254,9 @@ CREATE TABLE observation_period
      observation_period_id				INTEGER		NOT NULL , 
      person_id							INTEGER		NOT NULL , 
      observation_period_start_date		DATE		NOT NULL , 
+     observation_period_start_datetime		TIMESTAMP		NOT NULL ,
      observation_period_end_date		DATE		NOT NULL ,
+     observation_period_end_datetime		TIMESTAMP		NOT NULL ,
 	 period_type_concept_id				INTEGER		NOT NULL
     ) 
 ;
@@ -268,7 +270,7 @@ CREATE TABLE specimen
 	 specimen_concept_id				INTEGER			NOT NULL ,
 	 specimen_type_concept_id			INTEGER			NOT NULL ,
 	 specimen_date						DATE			NOT NULL ,
-	 specimen_time						VARCHAR(10)		NULL ,
+	 specimen_datetime						TIMESTAMP		NULL ,
 	 quantity							NUMERIC			NULL ,
 	 unit_concept_id					INTEGER			NULL ,
 	 anatomic_site_concept_id			INTEGER			NULL ,
@@ -302,9 +304,9 @@ CREATE TABLE visit_occurrence
      person_id						INTEGER			NOT NULL , 
      visit_concept_id				INTEGER			NOT NULL , 
 	 visit_start_date				DATE			NOT NULL , 
-	 visit_start_time				VARCHAR(10)		NULL ,
+	 visit_start_datetime				TIMESTAMP		NULL ,
      visit_end_date					DATE			NOT NULL ,
-	 visit_end_time					VARCHAR(10)		NULL , 
+	 visit_end_datetime					TIMESTAMP		NULL ,
 	 visit_type_concept_id			INTEGER			NOT NULL ,
 	 provider_id					INTEGER			NULL,
      care_site_id					INTEGER			NULL, 
@@ -321,6 +323,7 @@ CREATE TABLE procedure_occurrence
      person_id						INTEGER			NOT NULL , 
      procedure_concept_id			INTEGER			NOT NULL , 
      procedure_date					DATE			NOT NULL , 
+     procedure_datetime					TIMESTAMP			NOT NULL ,
      procedure_type_concept_id		INTEGER			NOT NULL ,
 	 modifier_concept_id			INTEGER			NULL ,
 	 quantity						INTEGER			NULL , 
@@ -340,8 +343,10 @@ CREATE TABLE drug_exposure
      person_id						INTEGER			NOT NULL , 
      drug_concept_id				INTEGER			NOT NULL , 
      drug_exposure_start_date		DATE			NOT NULL , 
-     drug_exposure_end_date			DATE			NULL , 
-     drug_type_concept_id			INTEGER			NOT NULL , 
+     drug_exposure_start_datetime		TIMESTAMP			NOT NULL ,
+     drug_exposure_end_date			DATE			NULL ,
+     drug_exposure_end_datetime			TIMESTAMP			NULL ,
+     drug_type_concept_id			INTEGER			NOT NULL ,
      stop_reason					VARCHAR(20)		NULL , 
      refills						INTEGER			NULL , 
      quantity						NUMERIC			NULL , 
@@ -367,8 +372,10 @@ CREATE TABLE device_exposure
      person_id						INTEGER			NOT NULL , 
      device_concept_id				INTEGER			NOT NULL , 
      device_exposure_start_date		DATE			NOT NULL , 
-     device_exposure_end_date		DATE			NULL , 
-     device_type_concept_id			INTEGER			NOT NULL , 
+     device_exposure_start_datetime		TIMESTAMP			NOT NULL ,
+     device_exposure_end_date		DATE			NULL ,
+     device_exposure_end_datetime		TIMESTAMP			NULL ,
+     device_type_concept_id			INTEGER			NOT NULL ,
 	 unique_device_id				VARCHAR(50)		NULL ,
 	 quantity						INTEGER			NULL ,
      provider_id					INTEGER			NULL , 
@@ -385,8 +392,10 @@ CREATE TABLE condition_occurrence
      person_id						INTEGER			NOT NULL , 
      condition_concept_id			INTEGER			NOT NULL , 
      condition_start_date			DATE			NOT NULL , 
-     condition_end_date				DATE			NULL , 
-     condition_type_concept_id		INTEGER			NOT NULL , 
+     condition_start_datetime			TIMESTAMP			NOT NULL ,
+     condition_end_date				DATE			NULL ,
+     condition_end_datetime				TIMESTAMP			NULL ,
+     condition_type_concept_id		INTEGER			NOT NULL ,
      stop_reason					VARCHAR(20)		NULL , 
      provider_id					INTEGER			NULL , 
      visit_occurrence_id			INTEGER			NULL , 
@@ -403,7 +412,7 @@ CREATE TABLE measurement
      person_id						INTEGER			NOT NULL , 
      measurement_concept_id			INTEGER			NOT NULL , 
      measurement_date				DATE			NOT NULL , 
-     measurement_time				VARCHAR(10)		NULL ,
+     measurement_datetime				TIMESTAMP		NULL ,
 	 measurement_type_concept_id	INTEGER			NOT NULL ,
 	 operator_concept_id			INTEGER			NULL , 
      value_as_number				NUMERIC			NULL , 
@@ -427,7 +436,7 @@ CREATE TABLE note
      note_id						INTEGER			NOT NULL , 
      person_id						INTEGER			NOT NULL , 
      note_date						DATE			NOT NULL ,
-	 note_time						VARCHAR(10)		NULL ,
+	 note_datetime						TIMESTAMP		NULL ,
 	 note_type_concept_id			INTEGER			NOT NULL ,
 	 note_text						TEXT	NOT NULL ,
      provider_id					INTEGER			NULL ,
@@ -444,7 +453,7 @@ CREATE TABLE observation
      person_id						INTEGER			NOT NULL , 
      observation_concept_id			INTEGER			NOT NULL , 
      observation_date				DATE			NOT NULL , 
-     observation_time				VARCHAR(10)		NULL , 
+     observation_datetime				TIMESTAMP		NULL ,
      observation_type_concept_id	INTEGER			NOT NULL , 
 	 value_as_number				NUMERIC			NULL , 
      value_as_string				VARCHAR(60)		NULL ,