In early March, 2021, CRA updated a number of its CEWS webpages.
Calculation - for periods 14-16:
the maximum wage subsidy rate for active employees will remain at 75%
the revenue drop will continue to compare your eligible revenue to a time prior to March 2020 (specific comparison months and years are listed for each claim period)
you may use a new pre-crisis pay period when calculating an employee’s pre-crisis pay (baseline remuneration) for the new claim periods
the maximum subsidy amount for employees on leave with pay will remain at $595
Baseline remuneration - election possibilities for periods 14 to 16 include:
January 1 to March 15, 2020 (75 days)
March 1 to June 30, 2019 (122 days)
July 1 to December 31, 2019 (184 days)
if the employee was on certain kinds of long-term leave from July 1, 2019, to March 15, 2020, the 90-day period ending before the leave started