If March 15th, 2012, was a Thursday, what day of the week was March 15th, 2014?

The correct answer is Saturday.

To determine the day of the week for March 15th, 2014, given that March 15th, 2012, was a Thursday, we calculate the number of extra days (odd days) accumulated over this time period.

Step 1: Understand the concept of odd days
A standard year consists of 365 days.
$365=(52\times 7)+1$
Because 52 full weeks account for 364 days, an ordinary year contributes exactly 1 odd day.
A leap year consists of 366 days and contributes 2 odd days due to the inclusion of February 29th.

Step 2: Analyze the relevant date interval
The timeframe is from March 15th, 2012, to March 15th, 2014.
Although 2012 was a leap year, February 29th, 2012, occurred before March 15th, 2012. Therefore, the leap day of 2012 is not within our given range.

Step 3: Count odd days year by year
1. From March 15th, 2012, to March 15th, 2013:
This interval spans 365 days (1 ordinary year), contributing 1 odd day.
2. From March 15th, 2013, to March 15th, 2014:
This interval also spans 365 days (1 ordinary year), contributing 1 odd day.
Total odd days accumulated:
$1+1=2\text{odd days}$

Step 4: Find the final day of the week
Adding 2 odd days to the initial day (Thursday):
$\text{Thursday}+1\text{day}=\text{Friday}$
$\text{Thursday}+2\text{days}=\text{Saturday}$
Thus, March 15th, 2014, was a Saturday.