reuse Lib.dateTick0

Author: archmoj

src/traces/scatter/attributes.js

@@ -43,8 +43,8 @@ function axisPeriod0(axis) {
             'Only relevant when the axis `type` is *date*.',
             'Sets the base for period positioning in milliseconds or date string on the ' + axis + ' axis.',
             'When `' + axis + 'period` is round number of weeks,',
-            'the `' + axis + 'period0` by default would be on a Sunday i.e. 1970-01-04,',
-            'otherwise it would be at 1970-01-01.'
+            'the `' + axis + 'period0` by default would be on a Sunday i.e. 2000-01-02,',
+            'otherwise it would be at 2000-01-01.'
         ].join(' ')
     };
 }

src/traces/scatter/period_defaults.js

@@ -8,15 +8,13 @@
 
 'use strict';
 
+var dateTick0 = require('../../lib').dateTick0;
 var numConstants = require('../../constants/numerical');
 var ONEWEEK = numConstants.ONEWEEK;
 
-function getPeriod0Dflt(period) {
+function getPeriod0Dflt(period, calendar) {
     var n = period / ONEWEEK;
-
-    return Math.round(n) === n ?
-        '1970-01-04' : // a Sunday
-        '1970-01-01';
+    return dateTick0(calendar, Math.round(n) === n);
 }
 
 module.exports = function handlePeriodDefaults(traceIn, traceOut, layout, coerce, opts) {
@@ -30,15 +28,15 @@ module.exports = function handlePeriodDefaults(traceIn, traceOut, layout, coerce
     if(opts.x) {
         var xperiod = coerce('xperiod');
         if(xperiod) {
-            coerce('xperiod0', getPeriod0Dflt(xperiod));
+            coerce('xperiod0', getPeriod0Dflt(xperiod, traceOut.xcalendar));
             coerce('xperiodalignment');
         }
     }
 
     if(opts.y) {
         var yperiod = coerce('yperiod');
         if(yperiod) {
-            coerce('yperiod0', getPeriod0Dflt(yperiod));
+            coerce('yperiod0', getPeriod0Dflt(yperiod, traceOut.ycalendar));
             coerce('yperiodalignment');
         }
     }