What is the APRS time format?
In an APRS weather data packet, the part between “@” and “z” is the time of the weather station clock when the packet was sent. However, many computer clocks frequently have large errors and to avoid these errors, the data time is taken as the time that the packet arrives at the findu.com server. This does introduce an error of the time that it took for the packet to travel from the station to the server, but that is usually not significant for weather uses. Marc, CW0009, operates a CWOP station in Antwerp, Belgium and has a time synced computer clock accurate to within one second. Marc sends four packets per hour on the quarter hour exactly. You can see Marc’s data here. The last two numbers in the time column are the time in seconds that it took to connect, send the packet through his ISP, across the Atlantic to the APRS-IS server, and to findu.com. This total time is usually between 10 and 20 seconds and is not a problem for our uses.
