The general principle is that accommodation and related meals will be reimbursed for the day before the conference begins extending to the night that the conference ends for accommodation, and to the day of departure for meals.
For example:
The conference extends from Monday to Wednesday, inclusive.
Allowable reimbursement
Costs for accommodation will normally be reimbursed for Sunday night to Wednesday night, inclusive. Meals (unless provided by the conference) may be claimed from Sunday to Thursday inclusive.
Exception
There may be exceptions where faculty members may have specific academic/scholarly reasons to arrive early or stay beyond the conference (i.e. collaboration with other faculty members, etc.). The reasons for an extended stay should be documented in reasonable detail, in order to be eligible for reimbursement (dates of meetings; names and titles of individuals attending meetings; their organization/institution; relevancy/nature of research/scholarly work).