diff --git a/hana/cds-plugin.js b/hana/cds-plugin.js
index 9f3d21fcb..b4d6fdbce 100644
--- a/hana/cds-plugin.js
+++ b/hana/cds-plugin.js
@@ -8,32 +8,36 @@ if (cds.requires.db?.impl === '@cap-js/hana') {
   cds.env.sql.dialect = 'hana'
 }
 
+// Consider that '-' is only allowed as timezone after ':' or 'T'
+const ISO = `FUNCTION ISO(RAW NVARCHAR(36))
+RETURNS RET TIMESTAMP LANGUAGE SQLSCRIPT AS
+BEGIN
+  DECLARE REGEXP NVARCHAR(255);
+  DECLARE TIMEZONE NVARCHAR(36);
+  DECLARE MULTIPLIER INTEGER;
+  DECLARE HOURS INTEGER;
+  DECLARE MINUTES INTEGER;
+  REGEXP := '(([-+])([[:digit:]]{2}):?([[:digit:]]{2})?|Z)$';
+  TIMEZONE := SUBSTR_REGEXPR(:REGEXP IN RAW GROUP 1);
+  RET := TO_TIMESTAMP(RAW);
+  IF :TIMEZONE = 'Z' OR :TIMEZONE IS NULL THEN
+    RETURN;
+  END IF;
+  MULTIPLIER := TO_INTEGER(SUBSTR_REGEXPR(:REGEXP IN TIMEZONE GROUP 2) || '1');
+  HOURS := TO_INTEGER(SUBSTR_REGEXPR(:REGEXP IN TIMEZONE GROUP 3));
+  MINUTES := COALESCE(TO_INTEGER(SUBSTR_REGEXPR(:REGEXP IN TIMEZONE GROUP 4)),0);
+  RET := ADD_SECONDS(:RET, (HOURS * 60 + MINUTES) * 60 * MULTIPLIER * -1);
+END;`
+
 // monkey patch as not extendable as class
 const compiler_to_hdi = cds.compiler.to.hdi
-cds.compiler.to.hdi = function capjs_compile_hdi(...args) {
+cds.compiler.to.hdi = Object.assign(function capjs_compile_hdi(...args) {
   const artifacts = compiler_to_hdi(...args)
-  artifacts['ISO.hdbfunction'] = 
-  `CREATE OR REPLACE FUNCTION ISO(RAW NVARCHAR(36))
-    RETURNS RET TIMESTAMP LANGUAGE SQLSCRIPT AS
-    BEGIN
-      DECLARE REGEXP NVARCHAR(255);
-      DECLARE TIMEZONE NVARCHAR(36);
-      DECLARE MULTIPLIER INTEGER;
-      DECLARE HOURS INTEGER;
-      DECLARE MINUTES INTEGER;
-      REGEXP := '(([-+])([[:digit:]]{2}):?([[:digit:]]{2})?|Z)$';
-      TIMEZONE := SUBSTR_REGEXPR(:REGEXP IN RAW GROUP 1);
-      RET := TO_TIMESTAMP(RAW);
-      IF :TIMEZONE = 'Z' OR :TIMEZONE IS NULL THEN
-        RETURN;
-      END IF;
-      MULTIPLIER := TO_INTEGER(SUBSTR_REGEXPR(:REGEXP IN TIMEZONE GROUP 2) || '1');
-      HOURS := TO_INTEGER(SUBSTR_REGEXPR(:REGEXP IN TIMEZONE GROUP 3));
-      MINUTES := COALESCE(TO_INTEGER(SUBSTR_REGEXPR(:REGEXP IN TIMEZONE GROUP 4)),0);
-      RET := ADD_SECONDS(:RET, (HOURS * 60 + MINUTES) * 60 * MULTIPLIER * -1);
-    END;`
-
+  artifacts['ISO.hdbfunction'] = ISO
   return artifacts
-}
+},
+{...compiler_to_hdi} // take over other stuff like keywords
+)
 
 // TODO: we can override cds.compile.to.sql/.delta in a similar fashion for our tests
+module.exports.ISO = ISO
diff --git a/hana/lib/HANAService.js b/hana/lib/HANAService.js
index 80211aac9..809a9b22f 100644
--- a/hana/lib/HANAService.js
+++ b/hana/lib/HANAService.js
@@ -60,6 +60,23 @@ class HANAService extends SQLService {
           const dbc = new driver(credentials)
           await dbc.connect()
           HANAVERSION = dbc.server.major
+
+          // Check whether the ISO function is available in the current deployment
+          if (!service.hasIsoFunction) {
+            service.hasIsoFunction = dbc.exec(`SELECT ISO('') FROM DUMMY`).catch(() => {
+              if (!service.class.CQN2SQL.InputConverters.Timestamp) {
+                service.class.CQN2SQL.InputConverters = service.class.CQN2SQL.InputConverters.__proto__
+              }
+            }, () => {
+              service.class.CQN2SQL.InputConverters = {
+                __proto__: service.class.CQN2SQL.InputConverters,
+                DateTime: undefined,
+                Timestamp: undefined
+              }
+            })
+          }
+          await service.hasIsoFunction
+
           return dbc
         } catch (err) {
           if (isMultitenant) {
@@ -137,7 +154,7 @@ class HANAService extends SQLService {
 
     // REVISIT: add prepare options when param:true is used
     const sqlScript = isLockQuery || isSimple ? sql : this.wrapTemporary(temporary, withclause, blobs)
-    let rows 
+    let rows
     if (values?.length || blobs.length > 0) {
       const ps = await this.prepare(sqlScript, blobs.length)
       rows = this.ensureDBC() && await ps.all(values || [])
diff --git a/hana/lib/drivers/base.js b/hana/lib/drivers/base.js
index 799ebbdc5..4d8241eb3 100644
--- a/hana/lib/drivers/base.js
+++ b/hana/lib/drivers/base.js
@@ -134,32 +134,6 @@ class HANADriver {
       minor: split[2],
       patch: split[3],
     }
-
-    // Consider that '-' is only allowed as timezone after ':' or 'T'
-    await prom(this._native, 'exec')(`
-    CREATE OR REPLACE FUNCTION ISO(RAW NVARCHAR(36))
-      RETURNS RET TIMESTAMP LANGUAGE SQLSCRIPT AS
-      BEGIN
-        DECLARE REGEXP NVARCHAR(255);
-        DECLARE TIMEZONE NVARCHAR(36);
-        DECLARE MULTIPLIER INTEGER;
-        DECLARE HOURS INTEGER;
-        DECLARE MINUTES INTEGER;
-
-        REGEXP := '(([-+])([[:digit:]]{2}):?([[:digit:]]{2})?|Z)$';
-        TIMEZONE := SUBSTR_REGEXPR(:REGEXP IN RAW GROUP 1);
-        RET := TO_TIMESTAMP(RAW);
-        IF :TIMEZONE = 'Z' OR :TIMEZONE IS NULL THEN
-          RETURN;
-        END IF;
-
-        MULTIPLIER := TO_INTEGER(SUBSTR_REGEXPR(:REGEXP IN TIMEZONE GROUP 2) || '1');
-        HOURS := TO_INTEGER(SUBSTR_REGEXPR(:REGEXP IN TIMEZONE GROUP 3));
-        MINUTES := COALESCE(TO_INTEGER(SUBSTR_REGEXPR(:REGEXP IN TIMEZONE GROUP 4)),0);
-
-        RET := ADD_SECONDS(:RET, (HOURS * 60 + MINUTES) * 60 * MULTIPLIER * -1);
-      END;
-    `)
   }
 
   /**
diff --git a/postgres/lib/PostgresService.js b/postgres/lib/PostgresService.js
index 8d9834002..97ea72d1f 100644
--- a/postgres/lib/PostgresService.js
+++ b/postgres/lib/PostgresService.js
@@ -500,8 +500,8 @@ GROUP BY k
       Int64: e => `CAST(${e} as bigint)`,
       Date: e => `CAST(${e} as DATE)`,
       Time: e => `CAST(${e} as TIME)`,
-      DateTime: e => `CAST(${e} as TIMESTAMP)`,
-      Timestamp: e => `CAST(${e} as TIMESTAMP)`,
+      DateTime: e => `CAST(${e} as TIMESTAMP WITH TIME ZONE)`,
+      Timestamp: e => `CAST(${e} as TIMESTAMP WITH TIME ZONE)`,
       // REVISIT: Remove that with upcomming fixes in cds.linked
       Double: (e, t) => `CAST(${e} as decimal${t.precision && t.scale ? `(${t.precision},${t.scale})` : ''})`,
       DecimalFloat: (e, t) => `CAST(${e} as decimal${t.precision && t.scale ? `(${t.precision},${t.scale})` : ''})`,
diff --git a/sqlite/lib/SQLiteService.js b/sqlite/lib/SQLiteService.js
index 0615c72a4..3e1d3cb81 100644
--- a/sqlite/lib/SQLiteService.js
+++ b/sqlite/lib/SQLiteService.js
@@ -27,7 +27,7 @@ class SQLiteService extends SQLService {
         const deterministic = { deterministic: true }
         dbc.function('session_context', key => dbc[$session][key])
         dbc.function('regexp', deterministic, (re, x) => (RegExp(re).test(x) ? 1 : 0))
-        dbc.function('ISO', deterministic, d => d && new Date(d).toISOString())
+        dbc.function('ISO', deterministic, d => d && new Date(/([+-]\d{2}:?(\d{2})?|Z)$/.test(d) ? d : `${d}Z`).toISOString())
 
         // define date and time functions in js to allow for throwing errors
         const isTime = /^\d{1,2}:\d{1,2}:\d{1,2}$/
diff --git a/test/cds.js b/test/cds.js
index ba0c89c18..bfe976d28 100644
--- a/test/cds.js
+++ b/test/cds.js
@@ -112,6 +112,11 @@ cds.test = Object.setPrototypeOf(function () {
   ret.data.autoIsolation(true)
 
   global.beforeAll(async () => {
+    if (cds.db.options.impl === '@cap-js/hana') {
+      await cds.run(`CREATE OR REPLACE ${require('../hana/cds-plugin.js').ISO}`)
+      await cds.disconnect() // Reset database connection to retrigger ISO detection
+    }
+
     if (ret.data._autoIsolation && !ret.data._deployed) {
       ret.data._deployed = cds.deploy(cds.options.from[0])
       await ret.data._deployed
diff --git a/test/compliance/resources/db/basic/literals/basic.literals.timestamp.js b/test/compliance/resources/db/basic/literals/basic.literals.timestamp.js
index 762556c2f..95805478e 100644
--- a/test/compliance/resources/db/basic/literals/basic.literals.timestamp.js
+++ b/test/compliance/resources/db/basic/literals/basic.literals.timestamp.js
@@ -4,32 +4,37 @@ module.exports = [
   },
   {
     timestamp: '1970-01-01T00:00:00.000Z',
-    '=timestamp': '1970-01-01T00:00:00.000Z',
+    '=timestamp': /1970-01-01T00:00:00.0000{0,6}Z/,
   },
   {
     timestamp: new Date('1970-01-01Z'),
-    '=timestamp': '1970-01-01T00:00:00.000Z',
+    '=timestamp': /1970-01-01T00:00:00.0000{0,6}Z/,
   },
   {
     timestamp: '1970-01-01T00:00:00.000Z',
+    '=timestamp': /1970-01-01T00:00:00.0000{0,6}Z/
   },
-  /* Ignoring transformations
+  {
+    timestamp: '2020-01-01T10:00:00.000+10:00',
+    '=timestamp': /2020-01-01T00:00:00.0000{0,6}Z/
+  },
+  /*
   {
     timestamp: '1970-01-01',
-    '=timestamp': '1970-01-01 00:00:00.0000000'
+    '=timestamp': /1970-01-01T00:00:00.0000{0,6}Z/
   },
   {
     timestamp: '1970-1-1',
-    '=timestamp': '1970-01-01 00:00:00.0000000'
+    '=timestamp': /1970-01-01T00:00:00.0000{0,6}Z/
   },
   {
     timestamp: '2',
-    '=timestamp': '0002-01-01 00:00:00.0000000'
+    '=timestamp': /0002-01-01T00:00:00.0000{0,6}Z/
   },
   {
     // HANA supports left trim
     timestamp: ' 2',
-    '=timestamp': '0002-01-01 00:00:00.0000000'
+    '=timestamp': /0002-01-01T00:00:00.0000{0,6}Z/
   },
   {
     // HANA does not support right trim
@@ -43,15 +48,15 @@ module.exports = [
   },
   {
     timestamp: '2-2',
-    '=timestamp': '0002-02-01 00:00:00.0000000'
+    '=timestamp': /0002-02-01T00:00:00.0000{0,6}Z/
   },
   {
     timestamp: '2-2-2',
-    '=timestamp': '0002-02-02 00:00:00.0000000'
+    '=timestamp': /0002-02-02T00:00:00.0000{0,6}Z/
   },
   {
     timestamp: () => new Date('1970-01-01Z'),
-    '=timestamp': '1970-01-01 00:00:00.0000000'
+    '=timestamp': /1970-01-01T00:00:00.0000{0,6}Z/
   },
   {
     // Z+2359 adds 23 hour and 59 minutes to the UTC time
@@ -68,26 +73,28 @@ module.exports = [
     timestamp: '1970-01-01+2359',
     '!': 'Invalid cds.Timestamp "1970-01-01+2359"'
   },
+  */
   {
     timestamp: '1970-01-01T01:10:59',
-    '=timestamp': '1970-01-01 01:10:59.0000000'
+    '=timestamp': /1970-01-01T01:10:59.0000{0,6}Z/
   },
   {
-    timestamp: '1970-01-01T00:00:00-2359',
-    '=timestamp': '1970-01-01 23:59:00.0000000'
+    timestamp: '1970-01-01T00:00:00-11:59',
+    '=timestamp': /1970-01-01T11:59:00.0000{0,6}Z/
   },
   {
     timestamp: '1970-01-01T00:00:00.999',
-    '=timestamp': '1970-01-01 00:00:00.9990000'
+    '=timestamp': /1970-01-01T00:00:00.9990{0,6}Z/
   },
   {
     timestamp: '1970-01-01T00:00:00.1234567',
-    '=timestamp': '1970-01-01 00:00:00.1234567'
+    '=timestamp': /1970-01-01T00:00:00.1234?5?6?7?0{0,2}Z/
   },
   {
     timestamp: '1970-01-01T00:00:00.123456789',
-    '=timestamp': '1970-01-01 00:00:00.1234567'
+    '=timestamp': /1970-01-01T00:00:00.1234?5?6?7?8?9?Z/
   },
+  /*
   {
     // HANA SECONDDATE does not support year 0 or lower
     timestamp: '0000-01-01',