General Principles
1.    Code: 441(a)-(e), (g); 446(a)-(d); 448(a); 451(a)
2.    Reg: 1.446-1(a)(1) to (3), (c), (d)
ii.    Timing is huge:
1.    rates may change from year to year; deductions and exceptions may change, t/f there may be huge difference b/w what you pay from year to year
2.    your filing status may change
3.    substantive rules of the tax code may change
4.    time value of money
iii.     441(c) & 451(a) are central to the timing of GI.  These provision constitute two of the three pillars of tax accounting:
1.    the annual accounting period (generally a 12 month period), &
2.    the permissible methods of tax accounting
3.    the third pillar, consisting of relief provisions, ameliorates the inequities that may result from the interaction of the rigid annual accounting concept and the progressive rate structure of federal income tax.
a.    these relief provisions include statutory and judicial rules, such as installment sale reporting, et operating loss carryovers, and non-recognition