平时 vs 平常 (usually / ordinary)

Usually, but not today

• Your grandfather normally goes to bed at nine, but tonight is New Year's Eve.
• (coll.) father's father爷爷yé yéusually平时píng shíat nine九点jiǔ diǎnthen / just就jiùto sleep睡shuì(completed / change)了le，today今天jīn tiānbut却quèall along一直yì zhíto wait until等到děng dào十二点shí èr diǎn。 — "Grandpa usually goes to bed at nine, but today he waited up until midnight."

usually平时píng shí = usually, in ordinary times (a time word)

• usually平时píng shí contrasts ordinary days with a special time: usually平时píng shívery很hěnbusy忙máng，at weekends周末zhōu mòonly then才cáiis free有空yǒu kòng.
• It can be a noun: with / and跟gēnusually平时píng shísame一样yī yàng — "the same as usual".

he他tāusually平时píng shívery很hěnbusy忙máng，at weekends周末zhōu mòonly then才cáiis free有空yǒu kòng。

ordinary平常píng cháng = usual, ordinary (adjective and time word)

• ordinary平常píng cháng can mean "usually" like usually平时píng shí: I / me我wǒordinary平常píng cháng七点qī diǎnto get out of bed起床qǐ chuáng.
• It can also be an adjective: "ordinary, common": this这zhèis是shìvery很hěnordinary平常píng cháng(modifier / structural particle)的dething事shì — "This is a very ordinary thing."

this这zhèis是shìvery很hěnordinary平常píng cháng的dething事shì。

Only ordinary平常píng cháng is an adjective

Versus generally通常tōng cháng

• generally通常tōng cháng = generally, as a rule, a little more formal: banks银行yín hánggenerally通常tōng chángat nine九点jiǔ diǎnopen开门kāi mén.
• usually平时píng shí / ordinary平常píng cháng are more about personal routine.

banks银行yín hánggenerally通常tōng chángat nine九点jiǔ diǎnopen开门kāi mén。

Recap

Read the full reference: HSK 5 grammar — Comparing similar time words.