5 replies to this topic

[Seany]

Hi

I don't even know if this is an install shield issue i suspect not but I wondered if anyone had seen it.

 

Some files when installed have a different modified time by one hour.

 

e.g. if you look at the file properties before the file is installed the last modified time might be 11:02. After installing the same file will show the time as 12:02.

 

It doesn't happen for all files and the difference always seems to be exactly 1 hour.

 

I suspected something to do with different time zones or British Summer time (Daylight Savings time) but cant quite figure out why or what changes the time after installing.

 

Has anyone seen this before?

 

Thanks

[Glytzhkof]

Perhaps you have set the wrong time zone for display? You may have set UTC + 1 which is central Europe. The UK is UTC (Greenwich Mean Time). Might be DST too - just check in the data and time dialog accessible from control panel or the system tray down at the right of the Windows Desktop.

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Edited by Glytzhkof, 27 November 2014 - 00:54.

[Seany]

Hi Thanks for your reply but I don't think that's the problem.

 

I might install 10 files (files created by my company) and for 6 the time seems OK but for the remaining 4 the time is different by an hour? 

 

It's very odd

[Glytzhkof]

This definitely has to do with DST I think - did you work on the files the day DST shifted? Have you worked on the files on different computers? How about computers with different time zones defined?

 

From Wikipedia: "...when files are copied or moved between NTFS and non-NTFS partitions, the OS needs to convert timestamps on the fly. But if some files are moved when daylight saving time (DST) is in effect, and other files are moved when standard time is in effect, there can be some ambiguities in the conversions. As a result, especially shortly after one of the days on which local zone time changes, users may observe that some files have timestamps that are incorrect by one hour."

 

A couple of other facts:

• From Wikipedia: "...Windows NT and its descendants keep internal timestamps as UTC and make the appropriate conversions for display purposes. Therefore, NTFS timestamps are in UTC."
• From CodeProject: "...Windows is stuck with some serious problems integrating FAT and NTFS files compatibly. FAT records file modification times with respect to the local time zone, while NTFS records file modification (as well as creation and access times, which FAT does not record) in UTC."
• From Microsoft: With regards to the  2-second (NTFS/FAT) time differences: "...when files are copied from NTFS drives to FAT drives, some file time stamp rounding has to occur; the file time stamp is rounded up to the next even second."

Edited by Glytzhkof, 27 November 2014 - 23:28.

[Seany]

Thank you for your great help Glytzhkof, I'll investigate the links you've supplied 

[Seany]

Hi again

 

I've done a bit more investigation and i'm still mystified.

 

I have the install kit on my machine (local drive Windows 7 NTFS system) i look at the properties  of an exe that is part of the install and the modified time is 13th March 2013 11:43.

 

I then run the install and when i look at the properties of the installed exe its modified time is 13th March 2013 12:43.

 

So 1 hour difference!

 

It does seem the act of installing somehow changes the time? I've tried just copying the exe from one folder to another and the time is ok. 

 

I tried changing the time zone of my machine and then installed. It made no difference the 1 hour difference still appeared. However when I changed my timezone back to GMT the modified time of the installed file changed to the time of the timezone I set when I installed the file!?

 

So I think something is going on with timezones/DST but still do not know what?