From 548396f87db576bfe2b9d80724554e51211d44f9 Mon Sep 17 00:00:00 2001
From: Lalo Martins <lalo.martins@gmail.com>
Date: Fri, 20 Mar 2020 08:44:37 +0200
Subject: [PATCH] Better DST handling
h/t @lalomartins @lemmingworks
Closes #1332 and related date issues
---
bits/20_jsutils.js | 8 +++++++-
test.js | 4 ++--
xlsx.flow.js | 8 +++++++-
xlsx.js | 8 +++++++-
4 files changed, 23 insertions(+), 5 deletions(-)
diff --git a/bits/20_jsutils.js b/bits/20_jsutils.js
index 97c0a14..40052fd 100644
--- a/bits/20_jsutils.js
+++ b/bits/20_jsutils.js
@@ -32,15 +32,21 @@ function evert_arr(obj/*:any*/)/*:EvertArrType*/ {
}
var basedate = new Date(1899, 11, 30, 0, 0, 0); // 2209161600000
-var dnthresh = basedate.getTime() + (new Date().getTimezoneOffset() - basedate.getTimezoneOffset()) * 60000;
function datenum(v/*:Date*/, date1904/*:?boolean*/)/*:number*/ {
var epoch = v.getTime();
if(date1904) epoch -= 1462*24*60*60*1000;
+ var dnthresh = basedate.getTime() + (v.getTimezoneOffset() - basedate.getTimezoneOffset()) * 60000;
return (epoch - dnthresh) / (24 * 60 * 60 * 1000);
}
+var refdate = new Date();
+var dnthresh = basedate.getTime() + (refdate.getTimezoneOffset() - basedate.getTimezoneOffset()) * 60000;
+var refoffset = refdate.getTimezoneOffset();
function numdate(v/*:number*/)/*:Date*/ {
var out = new Date();
out.setTime(v * 24 * 60 * 60 * 1000 + dnthresh);
+ if (out.getTimezoneOffset() !== refoffset) {
+ out.setTime(out.getTime() + (out.getTimezoneOffset() - refoffset) * 60000);
+ }
return out;
}
diff --git a/test.js b/test.js
index 93dfd69..23d3ea8 100644
--- a/test.js
+++ b/test.js
@@ -1422,10 +1422,10 @@ function seq(end/*:number*/, start/*:?number*/)/*:Array<number>*/ {
}
var basedate = new Date(1899, 11, 30, 0, 0, 0); // 2209161600000
-var dnthresh = basedate.getTime() + (new Date().getTimezoneOffset() - basedate.getTimezoneOffset()) * 60000;
function datenum(v/*:Date*/, date1904/*:?boolean*/)/*:number*/ {
var epoch = v.getTime();
- if(date1904) epoch += 1462*24*60*60*1000;
+ if(date1904) epoch -= 1462*24*60*60*1000;
+ var dnthresh = basedate.getTime() + (v.getTimezoneOffset() - basedate.getTimezoneOffset()) * 60000;
return (epoch - dnthresh) / (24 * 60 * 60 * 1000);
}
var good_pd_date = new Date('2017-02-19T19:06:09.000Z');
diff --git a/xlsx.flow.js b/xlsx.flow.js
index f6044bf..084f4c6 100644
--- a/xlsx.flow.js
+++ b/xlsx.flow.js
@@ -2751,15 +2751,21 @@ function evert_arr(obj/*:any*/)/*:EvertArrType*/ {
}
var basedate = new Date(1899, 11, 30, 0, 0, 0); // 2209161600000
-var dnthresh = basedate.getTime() + (new Date().getTimezoneOffset() - basedate.getTimezoneOffset()) * 60000;
function datenum(v/*:Date*/, date1904/*:?boolean*/)/*:number*/ {
var epoch = v.getTime();
if(date1904) epoch -= 1462*24*60*60*1000;
+ var dnthresh = basedate.getTime() + (v.getTimezoneOffset() - basedate.getTimezoneOffset()) * 60000;
return (epoch - dnthresh) / (24 * 60 * 60 * 1000);
}
+var refdate = new Date();
+var dnthresh = basedate.getTime() + (refdate.getTimezoneOffset() - basedate.getTimezoneOffset()) * 60000;
+var refoffset = refdate.getTimezoneOffset();
function numdate(v/*:number*/)/*:Date*/ {
var out = new Date();
out.setTime(v * 24 * 60 * 60 * 1000 + dnthresh);
+ if (out.getTimezoneOffset() !== refoffset) {
+ out.setTime(out.getTime() + (out.getTimezoneOffset() - refoffset) * 60000);
+ }
return out;
}
diff --git a/xlsx.js b/xlsx.js
index da15df5..8cfd42e 100644
--- a/xlsx.js
+++ b/xlsx.js
@@ -2672,15 +2672,21 @@ function evert_arr(obj) {
}
var basedate = new Date(1899, 11, 30, 0, 0, 0); // 2209161600000
-var dnthresh = basedate.getTime() + (new Date().getTimezoneOffset() - basedate.getTimezoneOffset()) * 60000;
function datenum(v, date1904) {
var epoch = v.getTime();
if(date1904) epoch -= 1462*24*60*60*1000;
+ var dnthresh = basedate.getTime() + (v.getTimezoneOffset() - basedate.getTimezoneOffset()) * 60000;
return (epoch - dnthresh) / (24 * 60 * 60 * 1000);
}
+var refdate = new Date();
+var dnthresh = basedate.getTime() + (refdate.getTimezoneOffset() - basedate.getTimezoneOffset()) * 60000;
+var refoffset = refdate.getTimezoneOffset();
function numdate(v) {
var out = new Date();
out.setTime(v * 24 * 60 * 60 * 1000 + dnthresh);
+ if (out.getTimezoneOffset() !== refoffset) {
+ out.setTime(out.getTime() + (out.getTimezoneOffset() - refoffset) * 60000);
+ }
return out;
}