Fix time zone issues in 32bit builds

The bug is obvious, tracking it down wasn't.
A simple thinko brought us time_t instead of timestamp_t - which doesn't
matter on 64bit builds, but makes things fail in weird ways on 32bit
builds - like our Windows binaries.
In this case instead of checking today's date to detect the timezone
offset we happened to be using a date in December 1969, so no dailight
savings, so the times were off.

Fixes #655
Fixes #667
See #670

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

2 files changed, 4 insertions, 4 deletions

diff --git a/helpers.h b/helpers.h
index 06a431779..56532d5c4 100644
--- a/helpers.h
+++ b/helpers.h
@@ -27,7 +27,7 @@ void set_default_dive_computer(const char *vendor, const char *product);
 void set_default_dive_computer_device(const char *name);
 QString getSubsurfaceDataPath(QString folderToFind);
 extern const QString get_dc_nickname(const char *model, uint32_t deviceid);
-int gettimezoneoffset(time_t when = 0);
+int gettimezoneoffset(timestamp_t when = 0);
 int parseTemperatureToMkelvin(const QString &text);
 QString get_dive_date_string(timestamp_t when);
 QString get_short_dive_date_string(timestamp_t when);
diff --git a/qt-gui.cpp b/qt-gui.cpp
index 0f5342921..e337a5ddd 100644
--- a/qt-gui.cpp
+++ b/qt-gui.cpp
@@ -372,7 +372,7 @@ QString getSubsurfaceDataPath(QString folderToFind)
 	return QString("");
 }
 
-int gettimezoneoffset(time_t when)
+int gettimezoneoffset(timestamp_t when)
 {
 	QDateTime dt1, dt2;
 	if (when == 0)
@@ -408,14 +408,14 @@ int parseTemperatureToMkelvin(const QString &text)
 QString get_dive_date_string(timestamp_t when)
 {
 	QDateTime ts;
-	ts.setMSecsSinceEpoch(when * 1000);
+	ts.setMSecsSinceEpoch(when * 1000L);
 	return loc.toString(ts.toUTC(), dateFormat + " " + timeFormat);
 }
 
 QString get_short_dive_date_string(timestamp_t when)
 {
 	QDateTime ts;
-	ts.setMSecsSinceEpoch(when * 1000);
+	ts.setMSecsSinceEpoch(when * 1000L);
 	return loc.toString(ts.toUTC(), shortDateFormat + " " + timeFormat);
 }