The Kolmogorov-Smirnov test (KS-test) tries to determine if two datasets differ significantly. The KS-test has the advantage of making no assumption about the distribution of data. (Technically speaking it is non-parametric and distribution free.) Note however, that this generality comes at some cost: other tests (for example Student's t-test) may be more sensitive if the data meet the requirements of the test. In addition to calculating the D statistic, this page will report if the data seem normal or lognormal. (If it is silent, assume normal data at your own risk!) It will enable you to view the data graphically which can help you understand how the data is distributed.
Programmers are procrastinators. Get in, get some coffee, check the mailbox, read the RSS feeds, read the news, check out latest articles on techie websites, browse through political discussions on the designated sections of the programming forums. Rinse and repeat to make sure nothing is missed. Go to lunch. Come back, stare at the IDE for a few minutes. Check the mailbox. Get some coffee. Before you know it, the day is over.