Mapping of timestamp is not clear whether timestamp shall specify only UTC time or whether local time can be used.
Standard merely states "MMS LastModified attribute" which permits either timestamp.
Since there is no 61850 (Ed1) mechanism to map local time to UTC, a client cannot interpret local times using only 61850 mechanisms.
Note: This is the only place in 61850 where "local time" seems to be permitted.
Note: This same issue is relevent to 61850-8-1 : 2011(=Ed2)
Proposal
Change text from:
"The IEC 61850-7-2 LastMOdified attribute shall be mapped tothe MMS file LastModified attribute"
to
"The IEC 61850-7-2 LastMOdified attribute shall be mapped tothe MMS file LastModified attribute using UTC semantics (i.e. with a trailing "Z")"