Both the budget forms from the application packages (SF424 (R&R) and PHS 398) and the All Personnel eSNAP screen in eRA Commons can accommodate partial months for all personnel. There are a couple of differences, however, and it relates to how we use the information.
The budget forms accommodate partial months up to two decimal places (e.g., 2.55 is an acceptable value) and less than a full month (e.g., .50 is an acceptable value) for any personnel. This allows you to document more precisely the level of effort for each individual who will be paid from the grant.
Your yearly progress report is not used by peer reviewers, so it doesn’t need to be as precise. However, it is used for reporting purposes and monitoring budget and personnel effort. The All Personnel eSNAP screen accommodates up to one decimal place (i.e., 1.2 academic months is an acceptable value), and you should include all personnel, regardless of their source of compensation.
On a related note, less than one person month can only be entered for PD/PIs in the All Personnel eSNAP screen. For all other personnel, only those who participate for one person month or more should be included in the All Personnel Report, regardless of their senior/key designation.