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<p class="MsoNormal"><span lang="EN-US" style="font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">Dear all,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-family:"Calibri",sans-serif;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">As discussed in today’s telecon I forward the email sent by Daniel Fischer.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-family:"Calibri",sans-serif;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">Best regards<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">Christian<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-family:"Calibri",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-family:"Calibri",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-family:"Calibri",sans-serif;mso-ligatures:none">From:</span></b><span lang="EN-US" style="font-family:"Calibri",sans-serif;mso-ligatures:none"> CESG <</span><a href="mailto:cesg-bounces@mailman.ccsds.org"><span lang="EN-US" style="font-family:"Calibri",sans-serif;mso-ligatures:none">cesg-bounces@mailman.ccsds.org</span></a><span lang="EN-US" style="font-family:"Calibri",sans-serif;mso-ligatures:none">>
<b>On Behalf Of </b>Daniel Fischer via CESG<br>
<b>Sent:</b> Dienstag, 28. Januar 2025 13:34<br>
<b>To:</b> </span><a href="mailto:cesg@mailman.ccsds.org"><span lang="EN-US" style="font-family:"Calibri",sans-serif;mso-ligatures:none">cesg@mailman.ccsds.org</span></a><span lang="EN-US" style="font-family:"Calibri",sans-serif;mso-ligatures:none"><br>
<b>Subject:</b> [CESG] CCSDS 2026 flavor of the Year 2038 problem<o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Dear all,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">In ESA we have noticed an issue with the time epoch in CCSDS implementations. Holger Dreihahns team has discovered the issue and he has condensed the information in the bellow message. We thought it would be important
to make also other CCSDS organisations aware of this and if you think this is relevant please inform your teams. Holger is of course available to provide more information as needed.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="xmsonormal" style="margin:0cm;margin-bottom:.0001pt"><span lang="EN-US" style="font-size:11.0pt;color:#212121">There seems to be a ‘<b>CCSDS 2026 flavor of the Year 2038 problem:</b></span><span lang="EN-US" style="font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:#172B4D">
</span><a href="https://eur05.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.us%2Fv3%2F__https%3A%2Fen.wikipedia.org%2Fwiki%2FYear_2038_problem__%3B!!PvBDto6Hs4WbVuu7!M1SRaXAY0DSSn92PD3lSg9EFSEqf-rGmUN-82qGLGGfsRkPZdUTmFuqj8iSDNU-bBwT7f86gSnO3eHpvtC8FhhzAkJJ5ixQZMpKI%24&data=05%7C02%7CDaniel.Fischer%40esa.int%7C9587005ad26d49b5a46e08dd3f8748e6%7C9a5cacd02bef4dd7ac5c7ebe1f54f495%7C0%7C0%7C638736572459321664%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=O1542NdAMGn4xPZ%2FyDJkUyn8oo3e4B5EnBgytM7oLvY%3D&reserved=0" title="Original URL:
https://urldefense.us/v3/__https:/en.wikipedia.org/wiki/Year_2038_problem__;!!PvBDto6Hs4WbVuu7!M1SRaXAY0DSSn92PD3lSg9EFSEqf-rGmUN-82qGLGGfsRkPZdUTmFuqj8iSDNU-bBwT7f86gSnO3eHpvtC8FhhzAkJJ5ixQZMpKI$
Click to follow link."><span lang="EN-US" style="font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:#96607D">https://en.wikipedia.org/wiki/Year_2038_problem</span></a><span lang="EN-US" style="font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:#172B4D">.</span><span lang="EN-US" style="font-size:11.0pt;color:#212121">
The CCSDS 2026 flavor of the problem potentially occurs 12 years before 2038 for dates as of 2026, as the CCSDS epoch of 1958 is twelve years before the UNIX epoch 1970.<o:p></o:p></span></p>
<p class="xmsonormal" style="margin:0cm;margin-bottom:.0001pt"><span lang="EN-US" style="font-size:11.0pt;color:#212121"><o:p> </o:p></span></p>
<p class="xmsonormal" style="margin:0cm;margin-bottom:.0001pt"><span lang="EN-US" style="font-size:11.0pt;color:#212121">In general, the problem occurs when a software stores the number of seconds since epoch in a signed 32bit integer.</span><span lang="EN-US" style="font-size:10.0pt;color:#212121">
</span><span lang="EN-US" style="font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:#172B4D">The problem may be subtle; see the following line of C++ having the problem for daysSinceEpoch > 24855:</span><span lang="EN-GB" style="font-size:10.0pt;color:#212121"><o:p></o:p></span></p>
<p class="xmsonormal"><span lang="EN-US" style="font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:#172B4D">
</span><span lang="EN-GB" style="font-size:10.5pt;font-family:"Courier New";color:#172B4D">int64_t secsSinceEpoch = daysSinceEpoch * 86400;</span><span lang="EN-US" style="font-size:10.5pt;font-family:"Courier New";color:#172B4D"><o:p></o:p></span></p>
<p class="xmsonormal" style="margin:0cm;margin-bottom:.0001pt"><span lang="EN-US" style="font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:#172B4D">Note: The CCSDS time standards are fine. However, software implementations of these standards may have
a problem. </span><span lang="EN-US" style="font-size:11.0pt;color:#212121">As such, organizations might want to check if systems are impacted.</span><span lang="EN-US" style="font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:#172B4D"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Kind Regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Daniel<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><u><span lang="EN-GB" style="font-size:7.5pt;font-family:"Verdana",sans-serif;color:gray;mso-fareast-language:EN-GB"> </span></u></b><span lang="EN-GB" style="font-size:8.5pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:EN-GB"><br>
</span><b><span lang="EN-GB" style="font-size:7.5pt;font-family:"Verdana",sans-serif;color:gray;mso-fareast-language:EN-GB">ESA – European Space Agency</span></b><span lang="EN-GB" style="font-size:7.5pt;font-family:"Verdana",sans-serif;color:gray;mso-fareast-language:EN-GB"><br>
Dr. Daniel Fischer (he/him) </span><span lang="EN-GB" style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#45B0E1;mso-fareast-language:EN-GB">I</span><span lang="EN-GB" style="font-size:7.5pt;font-family:"Verdana",sans-serif;color:#45B0E1;mso-fareast-language:EN-GB">
</span><span lang="EN-GB" style="font-size:7.5pt;font-family:"Verdana",sans-serif;color:#4C94D8;mso-fareast-language:EN-GB">Lead Ground Systems Engineering Architect</span><span lang="EN-GB" style="font-size:7.5pt;font-family:"Verdana",sans-serif;color:gray;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:7.5pt;font-family:"Verdana",sans-serif;color:gray;mso-fareast-language:EN-GB">Ground Segment Engineering and Innovation Department</span><span lang="EN-GB" style="font-size:8.5pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:EN-GB"><br>
</span><span lang="EN-GB" style="font-size:7.5pt;font-family:"Verdana",sans-serif;color:gray;mso-fareast-language:EN-GB">Directorate of Operations</span><span lang="EN-GB" style="font-size:8.5pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:EN-GB"><br>
</span><span lang="EN-GB" style="font-size:7.5pt;font-family:"Verdana",sans-serif;color:gray;mso-fareast-language:EN-GB">ESOC </span><span lang="EN-GB" style="font-size:7.5pt;font-family:"Arial",sans-serif;color:gray;mso-fareast-language:EN-GB">I</span><span lang="EN-GB" style="font-size:7.5pt;font-family:"Verdana",sans-serif;color:gray;mso-fareast-language:EN-GB"> Robert-Bosch-Str.
5, 64293 Darmstadt, Germany<br>
Tel: +49 6151 902718</span><span lang="EN-GB" style="font-size:8.5pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:EN-GB"><br>
</span><a href="mailto:Daniel.Fischer@esa.int"><span lang="EN-GB" style="font-size:7.5pt;font-family:"Verdana",sans-serif;color:#0563C1;mso-fareast-language:EN-GB">Daniel.Fischer@esa.int</span></a><span lang="EN-GB" style="font-size:7.5pt;font-family:"Verdana",sans-serif;color:gray;mso-fareast-language:EN-GB">
</span><span lang="EN-GB" style="font-size:7.5pt;font-family:"Arial",sans-serif;color:gray;mso-fareast-language:EN-GB">I</span><span lang="EN-GB" style="font-size:7.5pt;font-family:"Verdana",sans-serif;color:gray;mso-fareast-language:EN-GB"> </span><a href="http://www.esa.int/"><span lang="EN-GB" style="font-size:7.5pt;font-family:"Verdana",sans-serif;color:blue;mso-fareast-language:EN-GB">www.esa.int</span></a><span lang="EN-GB" style="mso-ligatures:none;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
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