Bug 916316 - Part 1: move MILLISECONDS_PER_ constants to GlobalConstants.
Bug 916316 - Part 2: extract DateUtils.
Bug 916316 - Part 3: reimplement date formatting, allow memoization of day formatting. Benchmark tests.
Bug 916316 - Part 4: memoize day formatting during document generation.
Review comment: introduce DateFormatter rather than memoizing.
Review comment: remove additional millisecond constants.
Review comment: rename getDateStringFormatter to getDateStringUsingFormatter.
Review comment: final.
Review comment: use a single DateFormatter throughout HealthReportGenerator.
Review comment: remove static getDateString.
Follow-up: truncate StringBuilder inside Formatter.
Bug 916316 - Speed up FHR date formatting. r=mcomella