There are some differences in where dates are placed in current IATI publishers' IATI-XML data files:

Hewlett:

• activity-date: start-planned, end-planned, on @iso-date attribute
• transaction-date: MISSING
• value-date: on value@value-date attribute

DFID:

• activity-date: ALL, placed within text, ends with Z
• transaction-date: on transaction-date@iso-date attribute, ends with Z
• value-date: on value@value-date attribute, ends with Z

WB:

• activity-date: start-actual, end-planned, placed within text and also on iso-date tag. (Also, tags are opened but empty in quite a few files - e.g. wb-in (e.g. 4th activity) and wb-vn.)
• transaction-date: on transaction-date@iso-date attribute
• value-date: MISSING (but value@value-date attribute is opened)

NL:

• activity-date: ALL, Placed on @iso-date attribute; often opened even when empty (e.g. end-actual)
• transaction-date: on transaction-date@iso-date attribute
• value-date: on value@value-date attribute

DIPR:

• activity-date: start-actual, end-planned, placed on @iso-date attribute
• transaction-date: on transaction-date@iso-date attribute
• value-date: on value@value-date attribute