BEG yy mm dd hh mm ss
and
END yy mm dd hh mm ss
in queries

BEG and END are primarily used when inserting records, to define the record's lifespan. However, as of v0.59 of the Wherehoo server, they may also be specified in queries, to retrieve records via temporal as well as geographic coordinates. For example, historical lookups may be run to perform analysis of expired records of subway activity or the "tracks" left by a person carrying a Wherehoo transponder.

In ordinary queries, BEG and END are not specified. The query returns all records that are "alive" at the moment the query is run. That is, their BEGIN times are before or equal to "now" and their end times are after or equal to "now".

When BEG and END are provided in a query, the default behavior is changed: the query will show all records that were active at any time between BEG and END. Note that such records may have expired before END or begun after BEG. The only requirement is that sometime between BEG and END, the record must have been active.

The illustrations below decribe both cases.

Default: BEG and END not specified in query

Records in red either expired before NOW
or don't begin until after NOW

All records in green are active "now" and will be returned by a query

BEG and END specified in query

Records in red had no active times between BEG and END

All records in green were active at least briefly during the interval (BEG..END) and will be returned by a query

Note that "now" is not a factor in the reqults when BEG and END are provided.

Warning: Don't use only one of BEG or END, use them both. Otherwise, the results will be quite confusing. To make BEG or END equal to now, just use '0 0 0 0 0 0' as the parameter to the command, for example: BEG 0 0 0 0 0 0