How to get uint64 from Gio.FileInfo

[Mz <mengzhuo1203 gmail com>]

Hi, Guys and Girls

Weird thing happened when I am trying to get File attribute from Gio.FileInfo

a = Gio.file_new_for_path('/home/meng/test') //a new file I just created.
b = a.query_info(Gio.FILE_ATTRIBUTE_TIME_MODIFIED,0,null)
c = b.get_attribute_uint64(Gio.FILE_ATTRIBUTE_TIME_MODIFIED)  //return
1343553596

when I try to covert "1343553596" into a Date instance, I found that
time-stamp is year 1970...
I also tried to run Number.MAX_VALUE and it return XX.E+308 which is
apparently more than UnixStamp's range.

b.get_modification_time().tv_sec //return 1343553596 as previous.

Now, I am totally surrender to this issue, can anyone enlighten me?