The optimal time for layoffs would have been back in mid October. More specifically, more than 60 days before December 25. This is because of federal law for layoffs.
Most Googlers have pre-stock-split grants that were granted in January of the previous 4 years. These grants can vest monthly if large enough, but for many Googlers the vestings are quarterly, semi-annually or annually.
This the December vesting was fairly large. Also, the January bonus payout is significant.
By not doing layoffs back in October, Google missed not paying those out.
Another key vesting date, although not as big, is March 25. 60 days prior is Tuesday, January 24. The Friday before that is January 20.
If Google was to have layoffs in the name of saving money, as some posters on this board suggest, then Google would have done so months ago. If Google is still serious about saving money in spite of missing that opportunity, there is a little less than two weeks to seize the next opportunity.
We will know for sure soon if layoffs are going to happen, or if the rumors were fake.