If you depict dates by day-month-year, not month-day-year, do not use commas. Make certain you use a consistent system throughout the document. Those disliking the required commas for month-day-year expressions used as adjectives (e.g., "your July 1, 2006, letter") might decide to use this form:
On 17 January 1945 he was born in a large southern city. We now wish to respond to your 1 July 2006 letter.
This technique, I should point out, is the one used in Great Britain. So if you're writing anything about to be sent over the pond, use the day-month-year approach.
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