Use source date epoch for draft publication time

Makefile

@@ -94,6 +94,9 @@ clean:
 
 ## Tests
 
+# Note that SOURCE_DATE_EPOCH=1234567890 corresponds to 1234567890 seconds
+# from the unix epoch (January 1, 1970), which is in 2009
+
 # Command used to invoke Inara. Sets an environment variable that makes the
 # program ignore the real date.
 INARA_TEST_CMD = docker run --rm \

data/filters/draft.lua

@@ -4,11 +4,15 @@
 --- resources/default-article-info.yaml
 function Meta (meta)
   if meta.draft and meta.draft ~= '' then
+    local epoch = os.getenv 'SOURCE_DATE_EPOCH'
+      and os.time { year = 1970, month = 1, day = 1, hour = 0, min = 0,
+                  sec = tonumber(os.getenv 'SOURCE_DATE_EPOCH') }
+      or os.time()
     meta.article.doi = '10.xxxxxx/draft'
     meta.article.issue = '¿ISSUE?'
     meta.article.volume = '¿VOL?'
     meta.published = 'unpublished'
-    meta.published_parts = os.date('*t')
+    meta.published_parts = os.date('*t', epoch)
     return meta
   end
 end

test/expected-draft/paper.tex

@@ -136,7 +136,7 @@
 \renewcommand{\footrulewidth}{0.25pt}
 
 \fancyfoot[L]{\parbox[t]{0.98\headwidth}{\footnotesize{\sffamily Krewinkel
-et al. (2024). Article Writing with Markdown and the Open Journals
+et al. (2009). Article Writing with Markdown and the Open Journals
 publishing pipeline. \emph{Journal of Open Source Software},
 \emph{¿VOL?}(¿ISSUE?), ¿PAGE? \url{https://doi.org/10.xxxxxx/draft}}.}}