Last-Modified Early dates before 1/1/1970

[AndrewD]

Am I right in thinking that Zoom has problems with files with "Last-Modified" dates earlier than 1/1/1970? Unfortunately, we have some legacy material that's older than that and I would ideally like to havethe correct date show up.

Also, is there any way to tag a file in its .desc file to say that there is no associated date?

[David]

It probably does yes. Web pages created during the 60's are pretty rare however (to say the least).

If you are using dates, then all files must have a date. Even if it is just the date when the file is indexed. Functions like sort by date wouldn't know what to do with files that have no dates.

[AndrewD]

It probably does yes. Web pages created during the 60's are pretty rare however (to say the least).

If you are using dates, then all files must have a date. Even if it is just the date when the file is indexed. Functions like sort by date wouldn't know what to do with files that have no dates.

Old web pages are indeed rare, for rather good reasons. However, old documents are not, and people expect that the search will give an accurate date.

It seems that Zoom's cgi engine folds dates before 1/1/70 to a date in the 2030's

[DavidB]

Just out of interest, this older legacy material... Are they files from a pre-1970 computer system? Or are they files that you have edited the date field so that it is recorded as being a pre-1970 date?

The reason I ask is that I found that Vista wouldn't let me set the system date earlier than 1/1/1980. Therefore I'm wondering if the OS won't deal with those dates is it possible for an application to do so?

[David]

Internally I think we are using Unix time (i.e a 32bit number in 32bit Windows) to represent the last modified date and time for documents. But I need to check this to be sure.

In 64bit Windows time becomes becomes 64bits. According to Wikipedia, "this goes back more than twenty times the age of the universe, and so suffices. In the positive direction, whether the approximately 293 billion representable years is truly sufficient depends on the ultimate fate of the universe, but it is certainly adequate for most practical purposes."

The 32bit representation seemed sufficient as it was difficult to have a last modified time on an electronic document earlier that 1/1/1970. Many of the operating systems functions also rely on this representation of time. So I don't think there will be an easy fix, but we'll have a look.

[AndrewD]

Just out of interest, this older legacy material... Are they files from a pre-1970 computer system? Or are they files that you have edited the date field so that it is recorded as being a pre-1970 date?

The reason I ask is that I found that Vista wouldn't let me set the system date earlier than 1/1/1980. Therefore I'm wondering if the OS won't deal with those dates is it possible for an application to do so?

They are a large set of pdf files, scanned from old documents, which are being retagged using Zoom's .desc feature. I suddenly discovered our 'founding papers' and early reports (an important part of history..) were appearing in the future