diff --git a/common/lib/__tests__/datatable_to_math_context.js b/common/lib/__tests__/datatable_to_math_context.js
index 66a0b857413d6..00c827e2b97df 100644
--- a/common/lib/__tests__/datatable_to_math_context.js
+++ b/common/lib/__tests__/datatable_to_math_context.js
@@ -7,6 +7,17 @@ describe('datatableToMathContext', () => {
   });
   it('filters out non-numeric columns and pivots datatable', () => {
     expect(datatableToMathContext(testTable)).to.be.eql({
+      time: [
+        1517842800950,
+        1517929200950,
+        1518015600950,
+        1517842800950,
+        1517929200950,
+        1518015600950,
+        1517842800950,
+        1517842800950,
+        1517842800950,
+      ],
       price: [605, 583, 420, 216, 200, 190, 67, 311, 288],
       quantity: [100, 200, 300, 350, 256, 231, 240, 447, 384],
     });
diff --git a/common/lib/datatable_to_math_context.js b/common/lib/datatable_to_math_context.js
index c288515dda2f7..9bf4a74559c1a 100644
--- a/common/lib/datatable_to_math_context.js
+++ b/common/lib/datatable_to_math_context.js
@@ -2,6 +2,8 @@ import { pivotObjectArray } from '../lib/pivot_object_array.js';
 
 // filters columns with type number and passes filtered columns to pivotObjectArray
 export function datatableToMathContext(datatable) {
-  const filteredColumns = datatable.columns.filter(col => col.type === 'number');
+  const filteredColumns = datatable.columns.filter(
+    col => col.type === 'number' || col.type === 'date'
+  );
   return pivotObjectArray(datatable.rows, filteredColumns.map(col => col.name));
 }
diff --git a/server/functions/__tests__/pointseries.js b/server/functions/__tests__/pointseries.js
index c13dfc14478d9..0a4ade77cee57 100644
--- a/server/functions/__tests__/pointseries.js
+++ b/server/functions/__tests__/pointseries.js
@@ -37,30 +37,6 @@ describe('pointseries', () => {
         rows: [{ x: 1, y: 2 }],
       });
     });
-    it('invalid args', () => {
-      expect(fn(testTable, { x: 'name', y: 'quantity * 3' })).to.be.eql({
-        type: 'pointseries',
-        columns: {
-          x: {
-            type: 'string',
-            role: 'dimension',
-            expression: 'name',
-          },
-          y: {
-            type: 'number',
-            role: 'measure',
-            expression: 'quantity * 3',
-          },
-        },
-        rows: [
-          { x: 'product1', y: null },
-          { x: 'product2', y: null },
-          { x: 'product3', y: null },
-          { x: 'product4', y: null },
-          { x: 'product5', y: null },
-        ],
-      });
-    });
     it('args with dimensions only', () => {
       expect(fn(testTable, { x: 'name', y: 'price', size: 'quantity' })).to.be.eql({
         type: 'pointseries',
@@ -161,5 +137,53 @@ describe('pointseries', () => {
         expect(row.y).to.be.within(0, 1);
       });
     });
+    it('empty string arg', () => {
+      expect(fn(testTable, { x: 'name', y: 'max(time)', size: '    ', text: '' })).to.be.eql({
+        type: 'pointseries',
+        columns: {
+          x: {
+            type: 'string',
+            role: 'dimension',
+            expression: 'name',
+          },
+          y: {
+            type: 'number',
+            role: 'measure',
+            expression: 'max(time)',
+          },
+        },
+        rows: [
+          { x: 'product1', y: 1518015600950 },
+          { x: 'product2', y: 1518015600950 },
+          { x: 'product3', y: 1517842800950 },
+          { x: 'product4', y: 1517842800950 },
+          { x: 'product5', y: 1517842800950 },
+        ],
+      });
+    });
+    it('invalid args', () => {
+      expect(fn(testTable, { x: 'name', y: 'quantity * 3' })).to.be.eql({
+        type: 'pointseries',
+        columns: {
+          x: {
+            type: 'string',
+            role: 'dimension',
+            expression: 'name',
+          },
+          y: {
+            type: 'number',
+            role: 'measure',
+            expression: 'quantity * 3',
+          },
+        },
+        rows: [
+          { x: 'product1', y: null },
+          { x: 'product2', y: null },
+          { x: 'product3', y: null },
+          { x: 'product4', y: null },
+          { x: 'product5', y: null },
+        ],
+      });
+    });
   });
 });
diff --git a/server/functions/pointseries/index.js b/server/functions/pointseries/index.js
index cf6f2ac15a24a..8f8f91d1abcbe 100644
--- a/server/functions/pointseries/index.js
+++ b/server/functions/pointseries/index.js
@@ -54,8 +54,7 @@ export const pointseries = () => ({
     // Separates args into dimensions and measures arrays by checking if arg is a column reference (dimension)
     Object.keys(args).forEach(arg => {
       const mathExp = args[arg];
-
-      if (mathExp != null) {
+      if (mathExp != null && mathExp.trim() !== '') {
         const col = {
           type: '',
           role: '',