Under AEDPA, a petitioner is not entitled to equitable tolling where he claims he reasonably believed there was an uncertainty about the legal rules governing the AEDPA because of uncertainty on the grounds for the state decision, and that he was deprived of his legal materials. The court noted that the threshold necessary to trigger equitable tolling is extremely high and the extraordinary circumstances that were alleged to have prevented compliance must be the result of an external force as opposed to oversight, negligence, or miscalculation. Petitioner was unable to meet this requirement to excuse his delay of 340 days. Although deprivation of legal materials can be the type of external impediment permitting a grant of equitable tolling, petitioner did not meet his burden of showing that the hardship caused the delay.