U.S. home values edged up 0.5% from February to March, making it the largest monthly increase in six years, real estate data firm Zillow ($33.45 0%) said in its latest home value index.

The data arrived the same week as Standard & Poor’s/Case-Shiller national indices report.

The S&P Case-Shiller note, which measures real estate data further out, said home values in nine metro areas reached record lows. S&P reported that its 10-city composite index experienced an annual home-price decline of 3.6% in February, while the 20-city composite index declined 3.5% from a year earlier.  

Zillow, which evaluates home prices in 30 markets using its value index, reported that nineteen markets have either reached a bottom in home prices or are expected to hit bottom by year’s end. 

Optimism is spreading over markets like Phoenix and Miami-Ft. Lauderdale, with Zillow estimating home price increases of 6.5% and 5.6%, respectively, in the two cities over the next year or so.

Nationally, home prices are expected to remain flat over the next 12 months, with values reaching a bottom in late 2012 and falling approximately 0.4% from the first quarter of 2012 to the first period of 2013, Zillow said.  

Metro areas like Chicago and Atlanta, on the other hand, are expected to see home price declines in the 3.8-to-4.1% range over the next 12 months.

“For people who have been waiting to time their home purchase close to market bottom, it’s time to start shopping,” said Zillow chief economist Dr. Stan Humphries. “When the bottom will hit will vary by market, and it’s nearly impossible to time a purchase exactly right. But home prices are not the only part of the equation. Buyers also should take into account the possibility that rising mortgage rates could offset any further home value declines that may occur.”