ang computation ng tax is annual.
now, dependa sa offer sayo. usual practice sa professional is annual salary, for example, and offer sayo is 1M/year. so kahit anung gawin nila na payment scheme, laging 1M ang total mo per year (all inclusive). pwedeng unang kinsenas 42k then katapusan is 38k. pwede ding monthly ka pasweldun na buong 80k.
may company naman (usually yung nasa middle class), monthly ang offer. so if 30k/mos ka, kahit febrary pa yan (28days), or december (301days), parehong 30k or 15k x 2 ang makukha mo.
now kung minimum wage ka. daily ka, then no work no pay.
hindi kasama sa salary computation ang allowance (optional yun eh).