What's that?

[RobertMika]

Add this custom format to any cell
[$-F4028C1]\:mm:ss
The type any Date or Time(time is prefered)

[ragulduy]

http://stackoverflow.com/questions/8...at-what-is-409

That seems to describe a similar problem, your number looks like hex so maybe this is the answer?
To clarify what others have said:

The [$-409] is a locale code, given in hexadecimal. Prefixing a date with a certain locale code determines what is shown when you use the various date time format codes. For example using the date

November 28, 1973 11:28:13 AM

as an example for the following table:

Format Code 409 (English United States) 804 (Chinese PRC)
=========== =========================== =================
m 11 11
mm 11 11
mmm Nov 十一月
mmmm November 十一月
d 27 27
dd 27 27
ddd Mon 二
dddd Monday 星期二
y 73 73
yy 73 73
yyy 1973 1973
yyyy 1973 1973
AM/PM AM 上午
So in the end the same format code with two different locale identifiers, gives different results:

[$-409]mmmm dd yyyy h:mm AM/PM
November 27 1973 11:28 AM


[$-804]mmmm dd yyyy h:mm AM/PM
十一月 27 1973 11:28 上午
Since finding a list of locale codes is like pulling teeth, here are some references:

Language Identifier Constants and Strings (Primary source)

Windows Locale Codes Sorted by Locale

Windows Locale Codes Sorted by Locale

[RobertMika]

Thank yudlugar for sharing this.