portability GNU `date` / Busybox `date`

diff --git a/file.sh b/file.sh
index 04a8ef617c9f755a4dcb7c3cf3adeeca69683f27..6f956dfeb5989a6b2542534d78134bc4633217de 100755 (executable)
--- a/file.sh
+++ b/file.sh
@@ -58,8 +58,7 @@ FILE(){
 
   file_size="$(stat -Lc %s "$file")"
   file_date="$(stat -Lc %Y "$file")"
-  http_date="$(date -uRd @$file_date)"
-  http_date="${http_date%+0000}GMT"
+  http_date="$(date -ud "@$file_date" +"%a, %d %b %Y %T GMT")"
   cachedate="$(
     # Parse the allowable date formats from Section 3.3.1 of
     # https://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html