The exact drop time varies by registry - from 30 to 60 days. It can take up to 75 days for the domain to actually drop. Contact the registrar to find out what their hold time is.
The domain will stay in pendingDelete for about 5 days. There is no set time for when a domain is dropped, though it does appear to start in the 11am-2pm PST (2pm - 5pm EST).
The domain finally dropped around 3:44 EST. The domain started with a C, so I thought that a bit late.
The domain was registered almost instantly by HugeDomains - a company that squats thousands of domains to resell at exorbitant prices ($1,200+).
Moral of the story: Back-order through a reputable company - multiple ones if you can.
The cost of back-ordering is much better than missing the domain all together. Auctions are rare, but even then, it's usually worth it.
[ Extra Data ]
I did an experiment tracking the status of several expiring domains over 3 days. The short version is: *if you search outside of the WHOIS Database, your domain is significantly more likely to be purchased by a competitor (i.e., reseller).**
Searching using only the WHOIS Internic does not guarantee others will not purchase the domain, but from the data I collected, the few that were purchased were registered with the intent to be used (not squatted) by parties far after the domain expired and became available again.