Add a plugin for Russian localization, make it be loaded first.

_plugins/1-i18n_filter.rb

@@ -0,0 +1,27 @@
+require 'i18n'
+
+LOCALE = :ru # set your locale
+
+# Create folder "_locales" and put some locale file from
+# https://github.com/svenfuchs/rails-i18n/tree/master/rails/locale
+module Jekyll
+  module I18nFilter
+    # Example:
+    #   {{ post.date | localize: "%d.%m.%Y" }}
+    #   {{ post.date | localize: ":short" }}
+    def localize(input, format=nil)
+      load_translations
+      format = (format =~ /^:(\w+)/) ? $1.to_sym : format
+      I18n.l input, :format => format
+    end
+
+    def load_translations
+      unless I18n::backend.instance_variable_get(:@translations)
+        I18n.backend.load_translations Dir[File.join(File.dirname(__FILE__), '../_locales/*.yml')]
+        I18n.locale = LOCALE
+      end
+    end
+  end
+end
+
+Liquid::Template.register_filter(Jekyll::I18nFilter)