--- a/taskcluster/ci/legacy/tasks/build.yml
+++ b/taskcluster/ci/legacy/tasks/build.yml
@@ -31,13 +31,13 @@ task:
       MOZ_BUILD_DATE: '{{pushdate}}'
       MOZ_SCM_LEVEL: '{{level}}'
 
   extra:
     build_product: '{{build_product}}'
     build_name: '{{build_name}}'
     build_type: '{{build_type}}'
     index:
-      rank: {{pushlog_id}}
+      rank: {{push_epoch}}
     treeherder:
       groupSymbol: tc
       groupName: Submitted by taskcluster
       symbol: B

--- a/taskcluster/ci/legacy/tasks/harness_test.yml
+++ b/taskcluster/ci/legacy/tasks/harness_test.yml
@@ -60,12 +60,12 @@ task:
     # These definitions are expected of build tasks but not used in our case
     build_product: '{{build_product}}'
     build_name: '{{build_name}}'
     build_type: '{{build_type}}'
     locations:
         build: null
         tests: null
     index:
-      rank: {{pushlog_id}}
+      rank: {{push_epoch}}
     treeherder:
       groupSymbol: tc
       groupName: Submitted by taskcluster

--- a/taskcluster/ci/legacy/tasks/lint.yml
+++ b/taskcluster/ci/legacy/tasks/lint.yml
@@ -32,9 +32,9 @@ task:
     cache:
       level-{{level}}-{{project}}-tc-vcs: '/home/worker/.tc-vcs'
 
   extra:
     build_product: '{{build_product}}'
     build_name: {{build_name}}
     build_type: {{build_type}}
     index:
-      rank: {{pushlog_id}}
+      rank: {{push_epoch}}

--- a/taskcluster/ci/legacy/tasks/phone_build.yml
+++ b/taskcluster/ci/legacy/tasks/phone_build.yml
@@ -56,13 +56,13 @@ task:
       GECKO_HEAD_REV: '{{head_rev}}'
       GECKO_HEAD_REF: '{{head_ref}}'
 
   extra:
     build_product: 'b2g'
     build_name: '{{build_name}}'
     build_type: '{{build_type}}'
     index:
-      rank: {{pushlog_id}}
+      rank: {{push_epoch}}
     treeherder:
       groupSymbol: tc
       groupName: Submitted by taskcluster
       symbol: B

--- a/taskcluster/taskgraph/kind/legacy.py
+++ b/taskcluster/taskgraph/kind/legacy.py
@@ -304,41 +304,44 @@ class LegacyKind(base.Kind):
 
         jobs = templates.load(job_path, {})
 
         job_graph, trigger_tests = parse_commit(message, jobs)
 
         cmdline_interactive = params.get('interactive', False)
 
         # Default to current time if querying the head rev fails
-        pushdate = time.strftime('%Y%m%d%H%M%S', time.gmtime())
+        push_epoch = int(time.time())
         vcs_info = query_vcs_info(params['head_repository'], params['head_rev'])
         changed_files = set()
         if vcs_info:
-            pushdate = time.strftime('%Y%m%d%H%M%S', time.gmtime(vcs_info.pushdate))
+            push_epoch = vcs_info.pushdate
 
             logger.debug('{} commits influencing task scheduling:'.format(len(vcs_info.changesets)))
             for c in vcs_info.changesets:
                 logger.debug("{cset} {desc}".format(
                     cset=c['node'][0:12],
                     desc=c['desc'].splitlines()[0].encode('ascii', 'ignore')))
                 changed_files |= set(c['files'])
 
+        pushdate = time.strftime('%Y%m%d%H%M%S', time.gmtime(push_epoch))
+
         # Template parameters used when expanding the graph
         parameters = dict(gaia_info().items() + {
             'index': 'index',
             'project': project,
             'pushlog_id': params.get('pushlog_id', 0),
             'docker_image': docker_image,
             'base_repository': params['base_repository'] or
             params['head_repository'],
             'head_repository': params['head_repository'],
             'head_ref': params['head_ref'] or params['head_rev'],
             'head_rev': params['head_rev'],
             'pushdate': pushdate,
+            'push_epoch': push_epoch,
             'pushtime': pushdate[8:],
             'year': pushdate[0:4],
             'month': pushdate[4:6],
             'day': pushdate[6:8],
             'owner': params['owner'],
             'level': params['level'],
             'from_now': json_time_from_now,
             'now': current_json_time(),