Change: Use ts for all timestamp-related selectors

This is much simpler, and it seems quite fast with the preambles.

README.org

@@ -144,27 +144,34 @@ Arguments are listed next to predicate names, where applicable.
 
 +  ~category (&optional categories)~ :: Return non-nil if current heading is in one or more of ~CATEGORIES~ (a list of strings).
 +  ~children (&optional query)~ :: Return non-nil if current heading has direct child headings.  If ~QUERY~, test it against child headings.  This selector may be nested, e.g. to match grandchild headings.
-+  ~clocked (&key from to on)~ :: Return non-nil if current entry was clocked in given period.  If no arguments are specified, return non-nil if entry was clocked at any time.  If ~FROM~, return non-nil if entry was clocked on or after ~FROM~.  If ~TO~, return non-nil if entry was clocked on or before ~TO~.  If ~ON~, return non-nil if entry was clocked on date ~ON~.  ~FROM~, ~TO~, and ~ON~ should be strings parseable by ~parse-time-string~ but may omit the time value.  Note: Clock entries are expected to be clocked out.  Currently clocked entries (i.e. with unclosed timestamp ranges) are ignored.
-+  ~closed (&optional comparator target-date)~ :: Return non-nil if entry's closed date compares with ~TARGET-DATE~ using ~COMPARATOR~.  ~TARGET-DATE~ should be a string parseable by ~date-to-day~.  ~COMPARATOR~ should be a function (like ~<=~).
-+  ~date (&optional comparator target-date type)~ :: Return non-nil if Org entry at point has date of ~TYPE~ that compares with ~TARGET-DATE~ using ~COMPARATOR~.  Checks all Org-formatted timestamp strings in entry.  ~TYPE~ may be ~active~, ~inactive~, or ~all~, to control whether active, inactive, or all timestamps are checked.  Ranges of each type are also checked.  ~TARGET-DATE~ should be a string parseable by ~date-to-day~.  ~COMPARATOR~ should be a function (like ~<=~).
-+  ~deadline (&optional comparator target-date)~ :: Return non-nil if entry's deadline compares with ~TARGET-DATE~ using ~COMPARATOR~.  ~TARGET-DATE~ should be a string parseable by ~date-to-day~; or if omitted, it is determined automatically using ~org-deadline-warning-days~. ~COMPARATOR~ should be a function (like ~<=~).
 +  ~descendants (&optional query)~ :: Return non-nil if current heading has descendant headings.  If ~QUERY~, test it against descendant headings.  This selector may be nested (if you can grok the nesting!).
 +  ~done~ :: Return non-nil if entry's ~TODO~ keyword is in ~org-done-keywords~.
 +  ~habit~ :: Return non-nil if entry is a habit.
 +  ~heading (regexp)~ :: Return non-nil if current entry's heading matches ~REGEXP~ (a regexp string).
 +  ~level (level-or-comparator &optional level)~ :: Return non-nil if current heading's outline level matches arguments.  The following forms are accepted: ~(level NUMBER)~: Matches if heading level is ~NUMBER~.  ~(level NUMBER NUMBER)~: Matches if heading level is equal to or between NUMBERs.  ~(level COMPARATOR NUMBER)~: Matches if heading level compares to ~NUMBER~ with ~COMPARATOR~.  ~COMPARATOR~ may be ~<~, ~<=~, ~>~, or ~>=~.
-+  ~planning (&optional comparator target-date)~ :: Return non-nil if entry's planning date (deadline or scheduled) compares with ~TARGET-DATE~ using ~COMPARATOR~.  ~TARGET-DATE~ should be a string parseable by ~date-to-day~.  ~COMPARATOR~ should be a function (like ~<=~).
 +  ~priority (&optional comparator-or-priority priority)~ :: Return non-nil if current heading has a certain priority.  ~COMPARATOR-OR-PRIORITY~ should be either a comparator function, like ~<=~, or a priority string, like "A" (in which case (~=~ will be the comparator).  If ~COMPARATOR-OR-PRIORITY~ is a comparator, ~PRIORITY~ should be a priority string.
 +  ~property (property &optional value)~ :: Return non-nil if current entry has ~PROPERTY~ (a string), and optionally ~VALUE~ (a string).  Note that property inheritance is currently /not/ enabled for this predicate.  If you need to test with inheritance, you could use a custom predicate form, like ~(org-entry-get (point) "PROPERTY" 'inherit)~.
 +  ~regexp (regexp)~ :: Return non-nil if current entry matches ~REGEXP~ (a regexp string).
-+  ~scheduled (&optional comparator target-date)~ :: Return non-nil if entry's scheduled date compares with ~TARGET-DATE~ using ~COMPARATOR~.  ~TARGET-DATE~ should be a string parseable by ~date-to-day~.  ~COMPARATOR~ should be a function (like ~<=~).
 +  ~tags (&optional tags)~ :: Return non-nil if current heading has one or more of ~TAGS~ (a list of strings).
 +  ~todo (&optional keywords)~ :: Return non-nil if current heading is a ~TODO~ item.  With ~KEYWORDS~, return non-nil if its keyword is one of ~KEYWORDS~ (a list of strings).  When called without arguments, only matches non-done tasks (i.e. does not match keywords in ~org-done-keywords~).
-+  ~ts (&key from to on type)~ :: Return non-nil if current entry has a timestamp in given period.  If no arguments are specified, return non-nil if entry has any timestamp.  If ~FROM~, return non-nil if entry has a timestamp on or after ~FROM~.  If ~TO~, return non-nil if entry has a timestamp on or before ~TO~.  If ~ON~, return non-nil if entry has a timestamp on date ~ON~.  ~FROM~, ~TO~, and ~ON~ should be either ~ts~ structs, or strings parseable by ~parse-time-string~ which may omit the time value.  ~TYPE~ may be ~active~ to match active timestamps, ~inactive~ to match inactive ones, or ~both~ / nil to match both types.
-+  ~ts-active~ :: Like ~ts~ called with ~:type active~.
-+  ~ts-a~ :: Like ~ts~ called with ~:type active~.
-+  ~ts-inactive~ :: Like ~ts~ called with ~:type inactive~.
-+  ~ts-i~ :: Like ~ts~ called with ~:type inactive~.
+
+*** Date/time selectors
+:PROPERTIES:
+:TOC:      ignore
+:END:
+
+All of these selectors take optional keyword arguments ~:from~, ~:to:~, and ~:on~.  If ~:from~, return non-nil if entry has a timestamp on or after ~:from~.  If ~:to~, return non-nil if entry has a timestamp on or before ~:to~.  If ~:on~, return non-nil if entry has a timestamp on date ~:on~.  Argument values should be either ~ts~ structs, or strings parseable by ~parse-time-string~ which may omit the time value.
+
++  ~clocked~ :: Return non-nil if current entry was clocked in given period.  If no arguments are specified, return non-nil if entry was clocked at any time.  Note: Clock entries are expected to be clocked out.  Currently clocked entries (i.e. with unclosed timestamp ranges) are ignored.
++  ~closed~ :: Return non-nil if current entry was closed in given period.  If no arguments are specified, return non-nil if entry was closed at any time.
++  ~deadline~ :: Return non-nil if current entry has deadline in given period.  If no arguments are specified, return non-nil if entry has any deadline.
++  ~planning~ :: Return non-nil if current entry has planning timestamp in given period (i.e. its deadline, scheduled, or closed timestamp).  If no arguments are specified, return non-nil if entry is scheduled at any time.
++  ~scheduled~ :: Return non-nil if current entry is scheduled in given period.  If no arguments are specified, return non-nil if entry is scheduled at any time.
++  ~ts~ :: Return non-nil if current entry has a timestamp in given period.  If no arguments are specified, return non-nil if entry has any timestamp.
++  ~ts-active~ :: Like ~ts~, but only matches active timestamps.
++  ~ts-a~ :: Like ~ts~, but only matches active timestamps.
++  ~ts-inactive~ :: Like ~ts~, but only matches inactive timestamps.
++  ~ts-i~ :: Like ~ts~, but only matches inactive timestamps.
 
 ** Functions / Macros
 :PROPERTIES:
@@ -382,6 +389,9 @@ Expands into a call to ~org-ql-select~ with the same arguments.  For convenience
 +  Macro ~org-ql~ no longer accepts a ~:markers~ argument.  Instead, use argument ~:action element-with-markers~.  See function ~org-ql-select~, which ~org-ql~ calls.
 +  Selector ~(todo)~ no longer matches "done" keywords when used without arguments (i.e. the ones in variable ~org-done-keywords~).
 
+*Removed*
++  Selector ~(date)~, replaced by ~(ts)~.
+
 *Fixed*
 +  Handle date ranges in date-based selectors.  (Thanks to [[https://github.com/codygman][Cody Goodman]], [[https://github.com/swflint][Samuel W. Flint]], and [[https://github.com/vikasrawal][Vikas Rawal]].)
 +  Don't overwrite bindings in =org-agenda-mode-map=.