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View of the Mainflingen long-wave radio station for transmission of the DCF77 signal:  transmitter building (in the back), antenna building (yellow bricks) and antenna masts.

The European telephone time code

Time code generated by the PTB telephone time-code generator

The European telephone time code, generated by PTB’s time code generator consists in a series of 80 ASCII characters which are emitted with a specific reference to the beginning of the second. The legal time, the coordinated universal time, the date including the numbers of the day of the week, the calendar week and the day of the year are, for example, transmitted. A sample line, valid for a point in time during Saturday, 2007-07-07, is shown above. The consecutive numbering of the characters transmitted is indicated above the sample line, and the letters below the sample line relate to the following explanation of the code content.

Code content:

A Year
B Month
C Day
D Hour
E This position normally contains „:“. When changeover from summer to standard time takes place, one hour is counted twice. The position can then contain “A“ and “B“ to make a distinction between the two identical hours. This distinction is necessary if the designation of the local time (see H) is not indicated.
F Minute
G Second
H Designation of local time
Identifies the time zone to which the local time belongs and indicates the state of the local time (standard time or summer time).
for Germany: MEZ Mitteleuropäische Zeit ( = Central European Time)
MESZ Mitteleuropäische Sommerzeit ( = Central European Summer Time)
I Day of the week (according to ISO 8601 / DIN EN 28601)
J Calendar week (according to ISO 8601 / DIN EN 28601)
K Number of day
L Month | Date and time for the next changeover
M Day | from standard time to summer time or vice versa
N Hour |  
O Year | Coordinated Universal Time
P Month |
Q Day |
R Hour |
S Minute |
The minute must be indicated, too, as the difference between local time and UTC may not only be composed of multiples of a complete hour.
T Modified Julian date (MJD)
(consecutive day counting, counted from Nov.17, 1858)
U Difference between Universal Time and Coordinated Universal Time (DUT1) in tenths of a second.
V Announcement of a leap second. It contains the sign of the leap second (“+“ or “-“) and the month in which it is inserted. In the example, a leap second is announced.
W Value of the assumed or measured (see Z) one way signal propagation time. Time in milliseconds by which the time code is emitted earlier.
X Figure between 0 and 9. Line counter for the message lines (see Y).
Y Part of a message of up to ten lines with a length of 14 characters which is transmitted in time multiplex.
Z Visible time marker. Normally the sign “*“. After a measurement of the signal propagation time and in accordance with previous time code emission, this sign is replaced by the sign “#“.
a The two characters CR and LF. The second change occurs during transition from the stop to the start bit of the two characters.

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