You will not be able to access either site (including Knowledge Base and eSupport) during this time.
Expect to see the following message:
To facilitate necessary online system updates, there is no access to PartnerSource or CustomerSource from February 26th through March 1st.
It is anticipated that all systems will be available again from 0800 hours (8am) on Monday March 1st. We apologize for any inconvenience caused by this maintenance.
Everything should be back to normal by Monday morning (US Time).