To figure out if a time word requires the particle ‘に,’ we ask if it refers to a specific time or a contextually dependent time. ‘こんばん’ (‘tonight’) changes meaning depending on the day it is said, so it does not require ‘に.’

To figure out if a time word requires the particle ‘に,’ we ask if it refers to a specific time or a contextually dependent time. ‘しゅうまつ’ (‘weekend’) changes meaning depending on the week that it is said, so it does not require ‘に.’ Note that this word in particular can take ‘に,’ but it is not required.

To figure out if a time word requires the particle ‘に,’ we ask if it refers to a specific time or a contextually dependent time. ‘あさ’ (‘morning’) changes meaning depending on the day that it is said, so it does not require ‘に.’ Note that words that refer to pieces of the day can take ‘に,’ but they don’t need to.

To figure out if a time word requires the particle ‘に,’ we ask if it refers to a specific time or a contextually dependent time. ‘いつ’ (‘when’) changes meaning depending on the context of the sentence, so it does not require ‘に.’

To figure out if a time word requires the particle ‘に,’ we ask if it refers to a specific time or a contextually dependent time. ‘きょう’ (‘today’) changes meaning depending on the day it is said, so it does not require ‘に.’

To figure out if a time word requires the particle ‘に,’ we ask if it refers to a specific time or a contextually dependent time. ‘いま’ (‘now’) changes meaning depending on when it is said, so it does not require ‘に.’

To figure out if a time word requires the particle ‘に,’ we ask if it refers to a specific time or a contextually dependent time. ‘どようび’ (‘Saturday’) always refers to the same day, regardless of when it is said, so it requires ‘に.’

To figure out if a time word requires the particle ‘に,’ we ask if it refers to a specific time or a contextually dependent time. ‘あした’ (‘tomorrow’) changes meaning depending on the day it is said, so it does not require ‘に.’

To figure out if a time word requires the particle ‘に,’ we ask if it refers to a specific time or a contextually dependent time. ‘じゅういちじ’ (’11 o’clock’) always refers to the same time regardless of when it is said, so it requires ‘に.’

To figure out if a time word requires the particle ‘に,’ we ask if it refers to a specific time or a contextually dependent time. ‘まいにち’ (‘every day’) refers to time generally, so it does not require ‘に.’

To figure out if a time word requires the particle ‘に,’ we ask if it refers to a specific time or a contextually dependent time. ‘まいばん’ (‘every night’) refers to time generally, so it does not require ‘に.’