diff --git a/README.md b/README.md
index 7f7be89..e01a6c6 100644
--- a/README.md
+++ b/README.md
@@ -143,7 +143,7 @@ The listing below is sorted based on LeetCode #. If you are interested to see my
 | 1145 | [Binary Tree Coloring Game](/problems/binary-tree-coloring-game/) | Medium | Tree, depth-first search |
 | 1150 | [Check If a Number Is Majority Element in a Sorted Array](/problems/is-a-a-majority-element) | Easy | Array, binary search |
 | 1153 | [String Transforms Into Another String](/problems/string-transforms-into-another-string) | Hard | Graph |
-| 1154 | [Day of the Year](/problems/ordinal-number-of-date) | Easy | Math |
+| 1154 | [Day of the Year](problems/day-of-the-year) | Easy | Math |
 | 1160 | [Find Words That Can Be Formed by Characters](/problems/find-words-that-can-be-formed-by-characters) | Easy | Array, hash table |
 | 1161 | [Maximum Level Sum of a Binary Tree](/problems/maximum-level-sum-of-a-binary-tree) | Medium | Graph |
 | 1162 | [As Far from Land as Possible](/problems/as-far-from-land-as-possible) | Medium | Breadth-first search, graph |
diff --git a/package-lock.json b/package-lock.json
index 0549bea..b4bb764 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "leetcode",
-  "version": "1.28.0",
+  "version": "1.28.1",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -631,9 +631,9 @@
       }
     },
     "@tootallnate/once": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/@tootallnate/once/-/once-1.0.0.tgz",
-      "integrity": "sha512-KYyTT/T6ALPkIRd2Ge080X/BsXvy9O0hcWTtMWkPvwAwF99+vn6Dv4GzrFT/Nn1LePr+FFDbRXXlqmsy9lw2zA==",
+      "version": "1.1.2",
+      "resolved": "https://registry.npmjs.org/@tootallnate/once/-/once-1.1.2.tgz",
+      "integrity": "sha512-RbzJvlNzmRq5c3O09UipeuXno4tA1FE6ikOjxZK0tuxVv3412l64l5t1W5pj4+rJq9vpkm/kwiR07aZXnsKPxw==",
       "dev": true
     },
     "@types/babel__generator": {
@@ -818,9 +818,9 @@
       "dev": true
     },
     "agent-base": {
-      "version": "6.0.0",
-      "resolved": "https://registry.npmjs.org/agent-base/-/agent-base-6.0.0.tgz",
-      "integrity": "sha512-j1Q7cSCqN+AwrmDd+pzgqc0/NpC655x2bUf5ZjRIO77DcNBFmh+OgRNzF6OKdCC9RSCb19fGd99+bhXFdkRNqw==",
+      "version": "6.0.1",
+      "resolved": "https://registry.npmjs.org/agent-base/-/agent-base-6.0.1.tgz",
+      "integrity": "sha512-01q25QQDwLSsyfhrKbn8yuur+JNw0H+0Y4JiGIKd3z9aYk/w/2kxD/Upc+t2ZBBSUNff50VjPsSW2YxM8QYKVg==",
       "dev": true,
       "requires": {
         "debug": "4"
@@ -1282,9 +1282,9 @@
       "dev": true
     },
     "codecov": {
-      "version": "3.6.5",
-      "resolved": "https://registry.npmjs.org/codecov/-/codecov-3.6.5.tgz",
-      "integrity": "sha512-v48WuDMUug6JXwmmfsMzhCHRnhUf8O3duqXvltaYJKrO1OekZWpB/eH6iIoaxMl8Qli0+u3OxptdsBOYiD7VAQ==",
+      "version": "3.7.2",
+      "resolved": "https://registry.npmjs.org/codecov/-/codecov-3.7.2.tgz",
+      "integrity": "sha512-fmCjAkTese29DUX3GMIi4EaKGflHa4K51EoMc29g8fBHawdk/+KEq5CWOeXLdd9+AT7o1wO4DIpp/Z1KCqCz1g==",
       "dev": true,
       "requires": {
         "argv": "0.0.2",
diff --git a/package.json b/package.json
index c8e5646..5902ea4 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "leetcode",
-  "version": "1.28.0",
+  "version": "1.28.1",
   "description": "My solutions for LeetCode problems.",
   "main": "index.js",
   "scripts": {
@@ -22,7 +22,7 @@
   },
   "homepage": "https://github.com/ecgan/leetcode",
   "devDependencies": {
-    "codecov": "^3.6.5",
+    "codecov": "^3.7.2",
     "eslint": "^6.8.0",
     "eslint-config-standard": "^14.1.0",
     "eslint-plugin-import": "^2.20.1",
diff --git a/problems/day-of-the-year/README.md b/problems/day-of-the-year/README.md
new file mode 100644
index 0000000..3472a5a
--- /dev/null
+++ b/problems/day-of-the-year/README.md
@@ -0,0 +1,46 @@
+# Day of the Year
+
+LeetCode #: [1154](https://leetcode.com/problems/day-of-the-year/)
+
+Difficulty: Easy
+
+Topics: Math.
+
+## Problem
+
+Given a string `date` representing a [Gregorian calendar](https://en.wikipedia.org/wiki/Gregorian_calendar) date formatted as `YYYY-MM-DD`, return the day number of the year.
+
+Example 1:
+
+```text
+Input: date = "2019-01-09"
+Output: 9
+Explanation: Given date is the 9th day of the year in 2019.
+```
+
+Example 2:
+
+```text
+Input: date = "2019-02-10"
+Output: 41
+```
+
+Example 3:
+
+```text
+Input: date = "2003-03-01"
+Output: 60
+```
+
+Example 4:
+
+```text
+Input: date = "2004-03-01"
+Output: 61
+```
+
+Constraints:
+
+- `date.length == 10`
+- `date[4] == date[7] == '-'`, and all other `date[i]`'s are digits
+- `date` represents a calendar date between Jan 1st, 1900 and Dec 31, 2019.
diff --git a/problems/ordinal-number-of-date/solution.js b/problems/day-of-the-year/dayOfYear.js
similarity index 100%
rename from problems/ordinal-number-of-date/solution.js
rename to problems/day-of-the-year/dayOfYear.js
diff --git a/problems/ordinal-number-of-date/solution.test.js b/problems/day-of-the-year/dayOfYear.test.js
similarity index 95%
rename from problems/ordinal-number-of-date/solution.test.js
rename to problems/day-of-the-year/dayOfYear.test.js
index 9f5edcf..216a6ae 100644
--- a/problems/ordinal-number-of-date/solution.test.js
+++ b/problems/day-of-the-year/dayOfYear.test.js
@@ -1,4 +1,4 @@
-const dayOfYear = require('./solution')
+const dayOfYear = require('./dayOfYear')
 
 test('Example 1', () => {
   const date = '2019-01-09'
diff --git a/problems/ordinal-number-of-date/README.md b/problems/ordinal-number-of-date/README.md
deleted file mode 100644
index 13dfebf..0000000
--- a/problems/ordinal-number-of-date/README.md
+++ /dev/null
@@ -1,7 +0,0 @@
-# Day of the Year
-
-[Link to LeetCode page](https://leetcode.com/problems/ordinal-number-of-date/)
-
-Difficulty: Easy
-
-Topics: -