AWS documentdb documentation change

Service: documentdb · 2026-03-31 · Documentation low

File: documentdb/latest/developerguide/dayOfMonth.md

Summary

Added new documentation page for the $dayOfMonth aggregation operator in Amazon DocumentDB, including syntax, parameters, MongoDB shell examples, and code examples in Node.js and Python with connection strings.

Security assessment

This change adds documentation for a date aggregation operator ($dayOfMonth) with standard usage examples. The code examples include TLS connection parameters (tls=true, tlsCAFile=global-bundle.pem) which are standard security practices for DocumentDB connections, but this is routine documentation of existing security features rather than addressing a specific security issue. No evidence of vulnerability remediation or security incident response.

Diff

diff --git a/documentdb/latest/developerguide/dayOfMonth.md b/documentdb/latest/developerguide/dayOfMonth.md
index 8b1378917..dc95d5164 100644
--- a//documentdb/latest/developerguide/dayOfMonth.md
+++ b//documentdb/latest/developerguide/dayOfMonth.md
@@ -0,0 +1 @@
+[](/pdfs/documentdb/latest/developerguide/developerguide.pdf#dayOfMonth "Open PDF")
@@ -1,0 +3,118 @@
+[Documentation](/index.html)[Amazon DocumentDB](/documentdb/index.html)[Developer Guide](what-is.html)
+
+Example (MongoDB Shell)Code examples
+
+# $dayOfMonth
+
+The `$dayOfMonth` aggregation operator in Amazon DocumentDB retrieves the day of the month (from 1 to 31) for a given date. This operator is useful for grouping, filtering, or extracting the day of the month from date fields in your documents.
+
+**Parameters**
+
+  * `date expression`: The date expression can be a date field from the document, a date object, or a date string.
+
+
+
+
+## Example (MongoDB Shell)
+
+This example demonstrates how to use the `$dayOfMonth` operator to extract the day of the month from a date field in the document.
+
+**Create sample documents**
+    
+    
+    db.events.insertMany([
+      { _id: 1, eventDate: new Date("2022-01-15T12:00:00Z") },
+      { _id: 2, eventDate: new Date("2022-02-28T15:30:00Z") },
+      { _id: 3, eventDate: new Date("2022-03-01T09:45:00Z") },
+      { _id: 4, eventDate: new Date("2022-04-30T23:59:59Z") }
+    ]);
+
+**Query example**
+    
+    
+    db.events.aggregate([
+      { $project: {
+        eventDay: { $dayOfMonth: "$eventDate" }
+      }}
+    ])
+
+**Output**
+    
+    
+    [
+      { "_id" : 1, "eventDay" : 15 },
+      { "_id" : 2, "eventDay" : 28 },
+      { "_id" : 3, "eventDay" : 1 },
+      { "_id" : 4, "eventDay" : 30 }
+    ]
+
+## Code examples
+
+To view a code example for using the `$dayOfMonth` command, choose the tab for the language that you want to use:
+
+Node.js
+    
+    
+    
+    const { MongoClient } = require('mongodb');
+    
+    async function example() {
+      const client = await MongoClient.connect('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false');
+      const db = client.db('test');
+      const events = db.collection('events');
+    
+      const result = await events.aggregate([
+        { $project: {
+          eventDay: { $dayOfMonth: "$eventDate" }
+        }}
+      ]).toArray();
+    
+      console.log(result);
+      await client.close();
+    }
+    
+    example();
+
+Python
+    
+    
+    
+    from pymongo import MongoClient
+    
+    def example():
+        client = MongoClient('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false')
+        db = client.mydatabase
+        events = db.events
+    
+        result = list(events.aggregate([
+            { "$project": {
+                "eventDay": { "$dayOfMonth": "$eventDate" }
+            }}
+        ]))
+    
+        print(result)
+        client.close()
+    
+    example()
+
+![Warning](https://d1ge0kk1l5kms0.cloudfront.net/images/G/01/webservices/console/warning.png) **Javascript is disabled or is unavailable in your browser.**
+
+To use the Amazon Web Services Documentation, Javascript must be enabled. Please refer to your browser's Help pages for instructions.
+
+[Document Conventions](/general/latest/gr/docconventions.html)
+
+$dateTrunc
+
+$dayOfWeek
+
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+
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+
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+
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+
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