Tony's already explained how you can populate a new field with the special format TW uses for dates. So you could populate a field yourself, and make the reasonable assumption that if the field is empty it doesn't contain a date. What exactly did you want to do with your own date field?
That said, the tool kit for date handling in TW is really sparse, which is frustrating. For instance, there's no mechanism for subtracting two dates. As a newcomer, you might wantto know about the tiddly toolmap: https://dynalist.io/d/zUP-nIWu2FFoXH-oM7L7d9DM#q=date This is one of the most comprehensive listings of the tools, plugins and kit available for TW. If you go there and plug in "date" in the search field, you'll likely find that others have already been putting together date tools that you might find helpful. TW's internal date stamps have other limitations. Like they only start in the 19th century, so aren't very useful for historical work. I've started on some date algorithms that use no javascript and work with dates in human readable format, like 2020-04-17 : https://marxsal.github.io/various/playground.html#Create%20a%20range%20of%20dates They can do things like calculate the number of days between dates. There hasn't been much enthusiasm expressed for them, but eventually I'd like to expand their abilities. Good luck! On Friday, April 17, 2020 at 3:51:01 PM UTC-7, grundyunderhill wrote: > > Thanks Tony! I appreciate you taking time to answer a post from a > relative newcomer in the forum! > > Your answer gave me some food for thought... Any of the built-in filter > operators which perform date calculations must allow for both timestamp > strings (such as returned by <<now "[UTC]YYYY0MM0DD0hh0mm0ssXXX">>) and > actual Date() objects (such as the "modified" or "created" field values), > same as mine does. So I looked at code for the "days" operator and saw > there is a built-in utility function ($tw.utils.parseDate) which > transparently handles either case. Not exactly what I was seeking, but > very helpful nonetheless! > > As for your view on JavaScript.... I can partially agree :) I too prefer > using built-in functionality whenever feasible. But on the other hand, > *somebody* has to write those community plugins, right? > > peace, > Nutt > > On Thursday, April 16, 2020 at 10:35:33 PM UTC-4, TonyM wrote: >> >> Nutt, >> >> I use date stamps a lot, especially to drive periodical items, for >> example a weekly-review field with a date stamp becomes due again once the >> date stamp is older than 7 days. I do not touch javascript. >> >> Here are some quick leads. >> >> - Set a field to the result of <<now "[UTC]YYYY0MM0DD0hh0mm0ssXXX">> >> see <https://tiddlywiki.com/#Date%20Fields> and this >> <https://tiddlywiki.com/#now%20Macro> >> - Use a button to setfield >> - Use the Date Picker Plugin http://kixam.github.io/TW5-datePicker/ >> >> Try this trick if you want to accept simple formatted dates >> <$edit-text field="date-field" field="myconfig" type="date"/> >> >> But then you would be wise to convert these to tiddlywiki date/time >> serial number to make full use of the days operator and more such as >> comparing with a system date or today. >> >> *Just ask if you come across some gaps!* >> >> It is my considered view if you are using javascript functions in >> tiddlywiki rather than its existing methods >> >> - You are doing it the wrong way >> - You have discovered a gap that should be considered as a new >> feature or a plugin to be developed for the community. >> >> >> Regards >> Tony >> >> >> On Friday, April 17, 2020 at 12:01:35 PM UTC+10, grundyunderhill wrote: >>> >>> Hi all, >>> Is there any way to make TW treat a user-defined field as a timestamp, >>> like it does for the built-in "created" and "modified" fields? >>> >>> My use case is that I want to capture timestamps of other events >>> (besides creation and modification), and be able to perform Date-related >>> calculations against them. Closest I've come so far is saving a string in >>> same format as it uses for "modified", and writing a custom filter operator >>> which calls $tw.Tiddler.fieldModules.modified.parse() to convert string to >>> Date object. It works, but I feel like it would be cleaner if I could just >>> check whether it's a Date already, and ignore everything else... >>> >>> Thanks, >>> Nutt >>> >> -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/tiddlywiki/00577654-8e76-4df7-814a-19ca920a7392%40googlegroups.com.
