You can tell you’re getting close to an Apple (AAPL) earnings report when the analysts start dusting off their spreadsheets and issuing new estimates. At least three came in on Monday.

• Needham’s Charlie Wolf made the biggest adjustment, hiking his earnings estimate to $10.85 from $9.55 on Street-high sales of $41.15 billion, up more than $3 billion from his previous estimate. He made the change, he writes, chiefly on reports of “blow-out” iPhone sales. He’s sticking with a 12-month price target of $540.
• Goldman Sachs’ Bill Shope raised his earnings estimate more modestly, to $9.87 from $9.44 on sales of $38.28 billion (up from an earlier estimate of $37.06 billion). Citing “several key catalysts” that should boost the stock in 2012, he raised his price target to $550 from $520.
• Hudson Square Research’s Daniel Ernst brought up the rear, raising his earnings estimate to $9.51 from $9.35 on sales of $37.3 billion (up from $36.8 billion). That still puts him near the bottom among the Wall Street analysts we’ve heard from. Never one of Apple’s strongest supporters, Ernst warns that rising Street estimates, particularly for the iPhone, set what he calls a high bar for the quarterly report due out Jan. 24.

Apple’s shares set an all-time intraday high of 427.75 in midmorning trading before giving up their gains at noon.