Tobias,
Thanks for your continued pointers. I'll need to digest what you wrote
below, but in the meantime, I found that your $setvars widget
(http://tobibeer.github.io/tw5-plugins/#setvars) solved my transclusion (if
not my GMT comprehension) problem. After finding a related prior
thread, [TW5] Passing a Transcluded Field Value to a Filter, I was able to
get the following code to filter for tiddlers that had the first 8
characters of their modified field matching the contents of !!date-search.
<$setvars _anchor="^" _date={{!!date-search}} dateRegExp="anchor date" >
__List of tiddlers with 'modified' field matching variable defined with
setvars =<<dateRegExp>>__ <br>
<$list filter="[regexp:modified<dateRegExp>]">
<$link><<currentTiddler>></$link> <$view field=modified format=date
template="YYYY0MM0DD" /> <br>
</$list>
</$setvars>
While I'm not clear on all the implications of timezone conversions, I do
wonder if part of my confusion is how TW interprets an 8 digit date field
when there is no time information present. For example, would a date field
containing only "20170108" always refer to this 8th day of January
regardless of time zone, or could TW possibly also take it to be the 7th
day in the western hemisphere because it pads it out to be 20170108000000
GMT = 20170107170000 in GMT - 7 for example? I find it more intuitive to
interpret "20170108" as a local date, without regard to time zone, always
associated with my journal tiddler from the 8th, but I can understand why
the mechanics of TW would want to handle 20170108 the same as 2017010800000.
This discussion does bring up a conceptual distinction question in my mind
about the behavior of the sameday operator. Are the two tiddler fields
20170101000001 and 20170101235959 in the same day everywhere as evaluated
by sameday[...], or does the answer depend on the time zone? If the answer
depends on the time zone, then I guess I need to record the "date only"
field in my journal tiddler to be YYYYMMDD070000 if I'm in UTC - 7. And
then I'd have to dynamically change this field if I shifted time zones.
Perhaps a better alternative is always using a macro that subtracts the
timezone offset from (adding 7 hours in my case) a specified 8 digit date
before using it as the parameter of the sameday operator.
I am under the impression that GMT and UTC both refer to a time rather than
a format, and that they are within a fraction of a second of each other.
For example, the header to your message below, generated by Google for
better or worse, gives a time in UTC - 7.
Thanks again for your continued insights,
Kevin
On Sunday, January 8, 2017 at 6:51:33 AM UTC-7, Tobias Beer wrote:
>
> As a general note,
>
> Make sure not to mix up UTC and GMT.
>
> UTC is a standard used for storing date-time information.
>
> GMT, however, refers to a timezone in UTC.
>
> [...]
>
--
You received this message because you are subscribed to the Google Groups
"TiddlyWiki" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/tiddlywiki.
To view this discussion on the web visit
https://groups.google.com/d/msgid/tiddlywiki/e12bfda4-3821-4f20-a0ba-400ec8e2387f%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
