Time Reference (C1 Only)

The Time Reference message is used to provide a midnight reference point for recipients of the feed. It is sent whenever the system starts up and when the system crosses a midnight boundary. All subsequent Time messages for the same unit will the use the last Midnight Reference until another Time Reference message is received for that unit. The Time Reference message includes the Trade Date, so most other sequenced messages will not include that information.

Time Reference messages will be included in a spin response.

Table 1. Time Reference
Field NameOffsetLengthType/(Value)Description
Length01BinaryLength of this message including this field.
Message Type110xB1 Time Reference Message
Midnight Reference24BinaryMidnight Eastern Time reference time for subsequent Time messages, expressed as number of whole seconds since the Epoch (midnight January 1, 1970 UTC).
Time64BinaryNumber of whole seconds elapsed since the start of the current Eastern Time calendar day, derived by converting the current Eastern wall clock time (HH:MM:SS) to seconds.

On Daylight Saving Time transition days, Time reflects wall clock seconds and does not adjust for the UTC offset change. On a DST spring-forward day, the maximum value will be 82,799 (23 hours). On a DST fall-back day, values between 3,600 and 7,199 will appear twice. Recipients requiring unambiguous absolute timestamps should use Epoch Time (where available) or Midnight Reference in the Time Reference message.

Time Offset104Time OffsetNanosecond offset from last unit timestamp.
Trade Date144Binary DateCurrent Trade Date
Total Length = 18 bytes
Cboe Titanium U.S. Options Auction Feed Specification - Time Reference (C1 Only) | Cboe