Market Data Advisory Notices
To | Market Data Distributors
From | Market Data Operations
Subject | IMPORTANT REMINDER - Daylight Savings Time Ends on November 4, 2007
Notice Date | 2007-10-24
Notice Number | Q2007-270
Effective Date | 2007-11-04
As a reminder, on Sunday, November 4, 2007, Daylight Savings Time (DST) will end at 2:00 a.m. Please be aware that for the first week only after the change takes effect and through the market close on November 9, the DST time change will not be updated within the MDP Wire Message Format/Message Timestamp field. (This format precedes the actual RLC and ITC 2.1 Message Specifications). MDP Wire Message Format/Message Timestamp Field As shown in the following MDP Message Wire Format illustration, the Message Timestamp uses 12:00 a.m. Sunday as its reference time. Even though the DST change will take place on Sunday, November 4, this information will not be reflected in the Message Timestamp until the following Sunday, November 11.
Field | Length | Description
HEADER
Message Sequence Number | 4 bytes (binary) | This represents the sequence number of the message within the published channel.
Message Timestamp | 4 bytes (binary) | This represents a timestamp for the publishing of the message. It is represented as the number of milliseconds since Sunday, 12 A.M. (00:00).
Message Body length | 2 bytes (binary) | This represents the length of the message body field.
BODY
Message Body |  | RLC – Compressed ITC 2.1– Plain text
If you have any questions on Sunday, November 4, 2007, please contact CME Enterprise Computer Operations at 312.930.8160 . Thank you.