diff --git a/CHANGES b/CHANGES
index 53beb38f..d2e72bd0 100644
--- a/CHANGES
+++ b/CHANGES
@@ -94,6 +94,8 @@ gcf 2.9:
     at once on Windows. (#824)
   * Define default initial sliver expirations for other Utah/PG AMs (Apt, Cloudlab, stitch). (#826)
     * Allow defining new such AMs in the omni config `omni_defaults` -> `utah_am_urns` (CSV).
+  * When calculating `expires` time to request, don't exceed the slice expiration,
+    and don't request less than some # of hours - 6 for APIv2, 3 for v3+. (#827)
 
  * Scripts
   * Initial commit of `examples/renewSliceAndSlivers.py`. (#798)
diff --git a/src/gcf/omnilib/stitch/objects.py b/src/gcf/omnilib/stitch/objects.py
index e760c45e..03fd48e0 100644
--- a/src/gcf/omnilib/stitch/objects.py
+++ b/src/gcf/omnilib/stitch/objects.py
@@ -957,9 +957,10 @@ def __init__(self, logger, opts):
             self.slicecred = _load_cred(MyHandler(self.logger, opts), opts.slicecredfile)
         sliceexp = get_cred_exp(self.logger, self.slicecred)
         sliceExpFromNow = naiveUTC(sliceexp) - now
-        minDays = sliceExpFromNow.days
+        minDays = max(sliceExpFromNow.days, 1) # Start out going for 1 day from now at least
         newExpires = naiveUTC(sliceexp)
         self.logger.debug("Starting newExpires at slice expiration %s, so init minDays to %d", sliceexp, minDays)
+        #self.logger.debug("now=%s", now)
 
         # Singleton for getting the default sliver expirations by AM type, that knows about values
         # from the omni_config
@@ -1043,6 +1044,17 @@ def __init__(self, logger, opts):
             # End loop over AMs on path
         # End loop over paths
 
+        minHours = 6
+        if self.api_version > 2:
+            minHours = allocHours
+        if naiveUTC(newExpires) - naiveUTC(now) < datetime.timedelta(hours=minHours):
+            self.logger.debug("Calculated new expiration within %d hour(s): reset to %d hour(s) from now", minHours, minHours)
+            newExpires = naiveUTC(now) + datetime.timedelta(hours=minHours)
+
+        if naiveUTC(sliceexp) < naiveUTC(newExpires):
+            self.logger.debug("Calculated new expiration after slice expiration: reset to slice expiration")
+            newExpires = sliceexp
+
         # In APIv3+, this should be a temporary hold. So only request the resources for a few hours.
         if self.api_version > 2:
             shortExpires = now + datetime.timedelta(hours=allocHours)