Merge pull request #5088 from plotly/improve-monthly-period-positioning

Improve monthly period label positioning

Author: archmoj

src/constants/numerical.js

@@ -33,7 +33,9 @@ module.exports = {
      */
     ONEAVGYEAR: 31557600000, // 365.25 days
     ONEAVGQUARTER: 7889400000, // 1/4 of ONEAVGYEAR
+    ONEMAXMONTH: 2678400000, // 31 * ONEDAY
     ONEAVGMONTH: 2629800000, // 1/12 of ONEAVGYEAR
+    ONEMINMONTH: 2419200000, // 28 * ONEDAY
     ONEWEEK: 604800000, // 7 * ONEDAY
     ONEDAY: 86400000,
     ONEHOUR: 3600000,

src/plots/cartesian/axes.js

@@ -25,7 +25,9 @@ var cleanTicks = require('./clean_ticks');
 var constants = require('../../constants/numerical');
 var ONEAVGYEAR = constants.ONEAVGYEAR;
 var ONEAVGQUARTER = constants.ONEAVGQUARTER;
+var ONEMAXMONTH = constants.ONEMAXMONTH;
 var ONEAVGMONTH = constants.ONEAVGMONTH;
+var ONEMINMONTH = constants.ONEMINMONTH;
 var ONEWEEK = constants.ONEWEEK;
 var ONEDAY = constants.ONEDAY;
 var ONEHOUR = constants.ONEHOUR;
@@ -780,8 +782,13 @@ axes.calcTicks = function calcTicks(ax, opts) {
                 v += ONEAVGYEAR / 2;
             } else if(delta >= ONEAVGQUARTER) {
                 v += ONEAVGQUARTER / 2;
-            } else if(delta >= ONEDAY * 28) { // Months could have days less than ONEAVGMONTH period
-                v += ONEAVGMONTH / 2;
+            } else if(delta >= ONEMINMONTH) { // Months could have days less than ONEAVGMONTH period
+                var actualDelta = Math.abs(B - A);
+                if(actualDelta >= ONEMINMONTH && actualDelta <= ONEMAXMONTH) {
+                    v += actualDelta / 2;
+                } else {
+                    v += ONEAVGMONTH / 2;
+                }
             } else if(delta >= ONEWEEK) {
                 v += ONEWEEK / 2;
             } else if(delta >= ONEDAY) {

test/jasmine/tests/axes_test.js

@@ -5297,14 +5297,14 @@ describe('Test axes', function() {
                 })
                 .then(function() {
                     _assert('', [
-                        '2019-12-16 05:15',
-                        '2020-01-16 05:15',
-                        '2020-02-16 05:15',
-                        '2020-03-16 05:15',
-                        '2020-04-16 05:15',
-                        '2020-05-16 05:15',
-                        '2020-06-16 05:15',
-                        '2020-07-16 05:15'
+                        '2019-12-16 12:00',
+                        '2020-01-16 12:00',
+                        '2020-02-15 12:00',
+                        '2020-03-16 12:00',
+                        '2020-04-16',
+                        '2020-05-16 12:00',
+                        '2020-06-16',
+                        '2020-07-16'
                     ], [
                         ['', '1-January', '1-February', '1-March', '2-April', '2-May', '2-June', ''],
                         ['', '1-Jan', '1-Feb', '1-Mar', '2-Apr', '2-May', '2-Jun', ''],