What does it mean to associate a note with time? For me, it is simply a way of capturing where that note fits into a timeline of events. I find this useful for two reasons: (1) it allows me another way to find notes I’m looking for; and (2) it provides a “big picture” look at a particular subject by seeing it over time. For example, maybe I need a copy of last year’s tax return. I could search for notes tagged #taxes, and then narrow that search by searching for notes in 2020 that are related to taxes. Or perhaps I’d like to see examples of my older daughter’s artwork. I could search for notes tagged #kids-art and #grace and sort the results by title, which includes a reference to the date. This allows me to see how that work evolved over time.
Different types of time
There are different types of time with which notes can be associated. Some of these associations happen automatically. For instance, when I create a note, the operating system stamps the file with a create date. When I make changes to a note, the operating system stamps the file with the last modified date. When I open a note, the operating system (at least on MacOS, which is where I primarily use Obsidian) also stamps the file with a “last viewed date. These all happen automatically, and while these dates can be changed, it requires some knowledge of Unix commands to change them. Besides, these are useful dates and changing them alters some useful information.
Then there is the date that I associate a note with on the timeline of my life. For me, this is the Zettelkasten prefix that I use in all of my note titles. This number, generated automatically when I create a new note, uses the format yyyymmddhhmm. I discussed this in some detail in Episode 6. Here is an example of a note for my older daughter’s birth certificate:
I’ll use this note to describe how these four times differ:
|Create date||9/29/2021 16:53||The time the file was created, which was back in September 2021.|
|Modified date||12/12/2021 9:22||The time the file was last modified, which was last Sunday.|
|Last opened||12/14/2021 9:29||The last time the file was opened.|
|Date prefix in note title||8/26/2011||The date matches the “issued on” date in the birth certificate.|
Of these date, the first three are set automatically by the operating system. The last one is generated automatically at the time I create the note, but I often change this to match the date on the document or note in question. In this case, I changed it to match the date the birth certificate was issued. I typically change this date to match the date on documents because this can be useful in a search, or in sorted related notes in a timeline of events.
The “Last Opened” date can be particularly useful, but currently, there appears to be a quirk with this date with respect to Obsidian. If I open an .md file in my vault from outside Obsidian–that is, if I double-click the file in Finder–then the Last Opened date gets updated. If I click on the note from within Obsidian, the Last Opened date does not get updated. This is something I’d love to see Obsidian add–updating the Last Opened date when a note is opened in Obsidian–for reasons I will explain shortly.
Associating notes with time
The most frequent time-related information I am looking for is where a note fits on a particular timeline. Since a document’s date rarely matches the create date of the note I associate it with (like the birth certificate above), I tend to use the Zettelkasten date prefix to associate my notes with time. For different types of documents, I might associate it slightly differently. A few examples:
- Official documents (like birth certificates, driver’s licenses, etc.): I use the “issued” date on the document.
- Letters and correspondence: I use the date on the letter (as opposed to the create date of the note, which is often the date the I received the letter.
- Statements and receipts: I use the statement date, or the date listed on the receipt.
Some notes aren’t associated with documents at all but still may represent events on a timeline. In these cases, I will alter the Zettelkasten prefix date to fit it where it belongs on the timeline in question. For instance, I may have a note about my youngest daughter losing her first tooth. I’ll make sure the prefix on that note reflects the date she actually lost her tooth, rather than the date I created the note.
Answering the “where” question: finding notes by time
Evernote is currently better at time-based searches than Obsidian, but I am hoping that Obsidian will improve on this over time. For instance, within Evernote, there are search parameters that allow you to search within time ranges based on created and modified dates. It is tricker to modified the created and modified dates in Evernote than it is the Zettelkasten prefix in Obsidian, but it is generally easier to do advance date searches in Evernote. That said, the Zettelkasten prefix often is enough to get me to the general area I am looking for.
Suppose, for instance, I needed to know when my current driver’s license was last issued. I know that we moved to our new house in June 2019, so I might start with a search for notes that are prefixed with 201906 (June 2019):
As it happened, this search returned just one note (mainly because I am still in the process of migrating notes from Evernote to Obsidian–more on this in Episode 14). But you can see how the formatting of the Zettelkasten prefix allows a general-to-specific date search and by getting to June 2019, I was quickly able to find what I was looking for: that the license was issued on June 10, 2019.
I don’t think it is possible to do date searches involving search operators in Obsidian yet, although there is a feature request for this. This is one area that Obsidian is currently lacking. A feature like this would allow for some sophisticated saved searches within Obsidian.
The value of “Last Opened” searches
One problem I had with Evernote is that there was no way to tell the last time you opened a note. All you could see was when you created it or last modified it. Often however, when I refer to a note, it is simply to read through it for some piece of information I need. I’m not actually changing it. “Last Opened” dates therefore provide a useful way of seeing notes that you’ve recently used–or even more useful to me, those notes that I haven’t looked at in a long, long time.
One way of keeping my vault useful is to purge it of those notes that I rarely or never use. Granted, there are certain notes that I might not refer to frequently, but are useful to keep around. But there are thousands of notes in Evernote that I scanned it just to get rid of the paper that I never went back and looked at again. These notes add noise to searches, and are essentially useless to me.
With my Obsidian vault, I have created a saved search (outside Obsidian for now) that shows me all of the note files in my vault that I haven’t opened in the last 6 months. I have this search saved in my Finder sidebar, and when I click on it, here is what I see for my current vault:
Notes that appear here are notes that I haven’t opened in more than 6 months. The list is fairly short right now because I started a fresh Obsidian vault around the time I started writing this series, gradually moving things over from Evernote and my old vault. More than likely, I’ll change this to > 1 year instead of 6 months and I’ll review what is in the list at the end of each year to see if there is anything I can purge.
Daily notes as a timeline of event
Another way I associate notes with time is through my daily notes. I have automated my daily notes so that I get a nice summary of events coming up on a given day. Then, I try to add notes throughout the day so that I know when things happened. Often, I’ll link to other notes so that when scanning my daily notes, I can see when something happened, but also, if I am looking at another note, a document maybe, I can see the daily note it was associated with in the backlinks. Here is an example from December 1:
Of course, this daily note also shows up in the backlink to Kelly’s COVID vaccination card, establishing it firmly on a timeline in both directions. Since I frequently live in my daily notes throughout the day, this is a great source of finding things by time. I’ll link to notes from phone calls I’ve had, documents I’ve received or sent, you name it. I’ll have a lot more to say about daily note in Episode 15.
In next week’s episode, I have a more philosophical post on what I think should be paperless (for me) and what stays on paper, as well as what goes into Obsidian and what can be left out. This is based on my own experience using tools like Evernote (and more recently Obsidian) for more than a decade. See you back here in a week!
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