diff --git a/Sources/MySQL/MySQL+Date.swift b/Sources/MySQL/MySQL+Date.swift
index 97bd6e9d..f8e3c5b7 100644
--- a/Sources/MySQL/MySQL+Date.swift
+++ b/Sources/MySQL/MySQL+Date.swift
@@ -1,10 +1,19 @@
 import Foundation
 
 public enum MySQLDateError: Swift.Error {
+    /**
+        Date wasn't a proper DATETIME-formatted String.
+     */
     case invalidDate
 }
 
 extension Date {
+    /**
+        Instantiates a `Date` from a MySQL DATETIME-formatted String.
+     
+        - Parameters:
+            - mysql: yyyy-MM-dd HH:mm:ss
+     */
     public init(mysql date: String) throws {
         guard let date = dateFormatter.date(from: date) else {
             throw MySQLDateError.invalidDate
@@ -13,11 +22,15 @@ extension Date {
         self = date
     }
     
+    /**
+        A MySQL DATETIME formatted String.
+     */
     public var mysql: String {
         return dateFormatter.string(from: self)
     }
 }
 
+// DateFormatter init is slow, need to reuse
 private var _df: DateFormatter?
 private var dateFormatter: DateFormatter {
     if let df = _df {