Workaround for ruby <3

checkdates.rb

@@ -3,13 +3,22 @@
 require 'yaml'
 require 'date'
 
+def yaml_load(text)
+  # not sure if 3.0.0 is the right threshold, but it works
+  if (RUBY_VERSION.split(".").map(&:to_i) <=> [3,0,0]) < 0
+    YAML.load(text)
+  else
+    YAML.load(text, permitted_classes: [Symbol, Date, Time])
+  end
+end
+
 class YAMLFrontMatter
   PATTERN = /\A(---\r?\n(.*?)\n?^---\s*$\n?)/m.freeze
 
   class << self
     def extract(content)
       if content =~ PATTERN
-        [YAML.load(Regexp.last_match(2), permitted_classes: [Symbol, Date, Time]), content.sub(Regexp.last_match(1), "")]
+        [yaml_load(Regexp.last_match(2)), content.sub(Regexp.last_match(1), "")]
       else
         [{}, content]
       end