Robert, I need to serialize ptime class instances. As far as I can tell, the ptime class isn't covered yet by serialization. However, if I understand how things work, I believe I can do it myself using split member. In the save() function, I would convert my ptime instance into a string, which I then serialize as a string. In the load() function, I would retrieve the string and construct another ptime instance. The other members of the class being serialized would be handled by the usual ar & <member_name>; with the appropriate NVP wrapper, since I'm using XML archives. Is that how I should do it? Merrill