you are a strange man, the key fact is not request.now, or request.utcnow but the fact that you can define your table to update these fields automatically so you can forget about them
db.define_table('your_table', Field('field1'), Field('field2'), Field("added_on", 'datetime', default=request.now), Field("updated_on", 'datetime', default=request.now, update=request.now), ) #then in controller db.insert(field1=some_value, field2=some_other_value) #added_on and updated_on are auto filled db.update(field1=.., field2=...) #only updated_on is auto filled hope you understand now my point db.update(field1=.., field2=..)