also check for M* dticks to avoid small errors with actual delta between two ticks

Author: archmoj

src/plots/cartesian/axes.js

@@ -820,19 +820,19 @@ axes.calcTicks = function calcTicks(ax, opts) {
             var delta = definedDelta || actualDelta;
             var periodLength = 0;
 
-            if(delta >= ONEMINYEAR) {
+            if(delta >= ONEMINYEAR || ax.dtick === 'M12') {
                 if(actualDelta >= ONEMINYEAR && actualDelta <= ONEMAXYEAR) {
                     periodLength = actualDelta;
                 } else {
                     periodLength = ONEAVGYEAR;
                 }
-            } else if(definedDelta === ONEAVGQUARTER && delta >= ONEMINQUARTER) {
+            } else if((definedDelta === ONEAVGQUARTER && delta >= ONEMINQUARTER) || ax.dtick === 'M3') {
                 if(actualDelta >= ONEMINQUARTER && actualDelta <= ONEMAXQUARTER) {
                     periodLength = actualDelta;
                 } else {
                     periodLength = ONEAVGQUARTER;
                 }
-            } else if(delta >= ONEMINMONTH) {
+            } else if(delta >= ONEMINMONTH || ax.dtick === 'M1') {
                 if(actualDelta >= ONEMINMONTH && actualDelta <= ONEMAXMONTH) {
                     periodLength = actualDelta;
                 } else {

test/image/baselines/date_axes_period_breaks_automargin.png

@@ -5704,7 +5704,7 @@ describe('Test axes', function() {
             },
             {
                 range: ['2020-12-15', '2022-12-15'],
-                positions: ['2020-10-16 05:15', '2021-01-16 05:15', '2021-04-16 05:15', '2021-07-16 05:15', '2021-10-16 05:15', '2022-01-16 05:15', '2022-04-16 05:15', '2022-07-16 05:15', '2022-10-16 05:15'],
+                positions: ['2020-11-16', '2021-02-15', '2021-05-16 12:00', '2021-08-16', '2021-11-16', '2022-02-15', '2022-05-16 12:00', '2022-08-16', '2022-11-16', ],
                 labels: [' ', 'Jan 2021', 'Apr 2021', 'Jul 2021', 'Oct 2021', 'Jan 2022', 'Apr 2022', 'Jul 2022', 'Oct 2022']
             },
             {
@@ -5825,7 +5825,7 @@ describe('Test axes', function() {
             },
             {
                 range: ['2022-12-15', '2020-12-15'],
-                positions: ['2023-01-16 05:15', '2022-10-16 05:15', '2022-07-16 05:15', '2022-04-16 05:15', '2022-01-16 05:15', '2021-10-16 05:15', '2021-07-16 05:15', '2021-04-16 05:15', '2021-01-16 05:15'],
+                positions: ['2023-02-16', '2022-11-16', '2022-08-15 12:00', '2022-05-16', '2022-02-16', '2021-11-16', '2021-08-15 12:00', '2021-05-16', '2021-02-15', ],
                 labels: [' ', 'Oct 2022', 'Jul 2022', 'Apr 2022', 'Jan 2022', 'Oct 2021', 'Jul 2021', 'Apr 2021', 'Jan 2021']
             },
             {