The noun ending -kor is used to express "at ... time". It may be added to the cardinal number or the word for hour:

• találkoztunk négykor we met at four (o'clock)
• találkoztunk négy órákor we met at four o'clock

Of course, -kor can apply to the demonstrative pronouns too, to give:

• az + -kor = akkor at that time
• ez + -kor = ekkor at this time

Akkor (at that time) is used as "then":

• mikor hazamesz? Akkor látlak. when are you coming home? I'll see you then (at that time). (When home-you-come? At-that-time I-see-you)

• amikor Budapesten reggel 8 óra van, akkor Londonban még csak 7 óra van. when in Budapest it's 8 in the morning, then in London it's still just 7.

• amikor Atlantában reggel 7 akkor Sydneyben már 14:00 van. when in New York it's 7 in the morning, then in Sydney it's already 23:00.

This ending can also be used to mean an era or an epoch. The most obvious is gyerekkor childhood.

For example: gyerekkoromban, nem voltam kövér in my childhood, I was not fat