prune: Use the local time zone (not UTC) when interpreting time

CHANGES

@@ -7,6 +7,8 @@ Version 0.12
 ------------
 
 (feature release, released on X)
+- ``attic prune`` now uses the local time zone (instead of UTC) when
+  determining which archives to keep.
 - ``attic mount`` now supports mounting an entire repository not only
   individual archives (#59)
 - Added option to restrict remote repository access to specific path(s):

attic/helpers.py

@@ -127,7 +127,7 @@ def prune_split(archives, pattern, n, skip=[]):
     if n == 0:
         return keep
     for a in sorted(archives, key=attrgetter('ts'), reverse=True):
-        period = a.ts.strftime(pattern)
+        period = to_localtime(a.ts).strftime(pattern)
         if period != last:
             last = period
             if a not in skip: