diff --git a/assets/clone.html b/assets/clone.html
index cefb64d..2c2f8c8 100644
--- a/assets/clone.html
+++ b/assets/clone.html
@@ -451,13 +451,13 @@
 								</select>
 
 								<select id="expiry" name="expiry" class="form-control">
-									<option value="5M">5 minutes</option>
-									<option value="1H">1 hour</option>
-									<option value="1D">1 day</option>
-									<option value="1W">1 week</option>
-									<option value="30D">1 month</option>
-									<option value="1Y">1 year</option>
-									<option value="20Y" selected>Forever</option>
+									<option value="P5M">5 minutes</option>
+									<option value="P1H">1 hour</option>
+									<option value="P1D">1 day</option>
+									<option value="P1W">1 week</option>
+									<option value="P30D">1 month</option>
+									<option value="P1Y">1 year</option>
+									<option value="P20Y" selected>Forever</option>
 								</select>
 						
 								<button type="submit" class="btn btn-raised btn-primary">Submit<div class="ripple-container"></div></button>
diff --git a/assets/index.html b/assets/index.html
index 50914ed..5bd36c1 100644
--- a/assets/index.html
+++ b/assets/index.html
@@ -450,13 +450,13 @@
 								</select>
 
 								<select id="expiry" name="expiry" class="form-control">
-									<option value="5M">5 minutes</option>
-									<option value="1H">1 hour</option>
-									<option value="1D">1 day</option>
-									<option value="1W">1 week</option>
-									<option value="30d">1 month</option>
-									<option value="1Y">1 year</option>
-									<option value="20Y" selected>Forever</option>
+									<option value="P5M">5 minutes</option>
+									<option value="P1H">1 hour</option>
+									<option value="P1D">1 day</option>
+									<option value="P1W">1 week</option>
+									<option value="P30d">1 month</option>
+									<option value="P1Y">1 year</option>
+									<option value="P20Y" selected>Forever</option>
 								</select>
 								<button type="submit" class="btn btn-raised btn-primary">Submit<div class="ripple-container"></div></button>
 							</div>