Hello,<br/><br/>Are all of these examples correct? And which of these examples are acceptable in American English? <br/><br/>Her birhtday is October 15th. <br/><br/>Her birthday is on october 15, 2011. <br/><br/>Today it's October 15, 2011.<br/><br/>Today it's 25 November.<br/><br/>It happened on 25 September 2011.<br/><br/>It happened on September 25rd, 2011.<br/><br/><b> </b><br/><br/>I noticed that the 'on' 'the' 'of' can be omitted sometimes, but I don't know when.<br/><br/>Thanks<br/>