Dear Tracy, My apologies for the confusion. I didn't (and can't) create the field in the API - I found it in the API documentation: "https://support.workfront.com/hc/en-us/articles/220633507-API-Explorer/support.workfront.com/hc/en-us/articles/220633507-API-Explorer"
https://support.workfront.com/hc/en-us/articles/220633507-API-Explorer (Filter on 'Task', and then scroll through the alphabetically sorted list to 'Days Late' All I know about it is that it's field type is integer - I don't know the formula / logic behind it, but looking at the name and output indicates it does what it says on the box. I can include it as a column in a report without going into text mode, but it isn't available as a choice on the filter page, and putting another integer field in the filter, changing to text mode and replacing the filed name with daysLate doesn't work. Regards, Barry Buchanan Work Management Australia