No, the date is accurate. We did that with another ES in MCPS. The old school is demolished the day after the school year ends (so for Candlewood, it must have been June 2013) and construction begins immediately. It's about 18 months for the construction process.
If your child starts at Candlewood next year (meaning August 2014), a few months at the holding school won't be an issue. Even if you buy the house there prior to June 2014, a few months of this school year + the first half of the 2014-2015 school year, should be a big deal, either.