diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 1d5cbc19..60d2053f 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -6,6 +6,10 @@ on:
       - 'develop'
   pull_request:
     types: [edited, ready_for_review, opened, synchronize, reopened]
+    paths-ignore:
+      - '.github/workflows/**'
+      - 'site/**'
+      - '**/*.md'
 
 jobs:
   cache:
diff --git a/.github/workflows/schedule.yml b/.github/workflows/schedule.yml
index 257eed43..c877f7ea 100644
--- a/.github/workflows/schedule.yml
+++ b/.github/workflows/schedule.yml
@@ -17,11 +17,17 @@ jobs:
         run: |
           default_branch=$(gh api /repos/$REPO | jq -r '.default_branch')
 
-          last_commit_time=$(date +%s \
-            -d $(gh api /repos/${REPO}/branches/${default_branch} | jq -r '.commit.commit.author.date'))
+          last_commit_date=$(gh api /repos/${REPO}/branches/${default_branch} | jq -r '.commit.commit.author.date')
 
-          last_night_time=$(date +%s \
-            -d $(gh api /repos/${REPO}/actions/workflows/schedule.yml/runs | jq -r '.workflow_runs[].updated_at' | sort | tail -1))
+          last_night_date=$(gh api /repos/${REPO}/actions/workflows/schedule.yml/runs | \
+            jq -r '.workflow_runs[]? | select((.status == "completed")) | .updated_at' \
+            | sort | tail -1)
+
+          last_night_time=$(date +%s -d $last_night_date)
+          last_commit_time=$(date +%s -d $last_commit_date)
+
+          echo Last CI-nightly workflow run time: $last_night_date
+          echo Last commit time in develop branch: $last_commit_date
 
           echo ::set-output name=last_commit_time::${last_commit_time}
           echo ::set-output name=last_night_time::${last_night_time}