ごろ details

ごろ

around; about (a point in time)

今日きょうは六時ろくじごろ帰かえれそう。

kyou wa rokuji goro kaeresou.

Looks like I can get home around six today. casual

引ひっ越こしは来月らいげつごろになりそうです。

hikkoshi wa raigetsu goro ni narisou desu.

The move is looking like it will be around next month. neutral

Examples

around; about — hedges a clock time or a date without committing to it

今日きょうは六時ろくじごろ帰かえれそう。

kyou wa rokuji goro kaeresou.

Looks like I can get home around six today. casual

引ひっ越こしは来月らいげつごろになりそうです。

hikkoshi wa raigetsu goro ni narisou desu.

The move is looking like it will be around next month. neutral

開演かいえんは六時ろくじごろを予定よていしております。

kaien wa rokuji goro o yotei shite orimasu.

We expect the performance to begin around six. formal

頃 — the same word in kanji — the suffix is normally written ごろ in kana, and ころ is the reading it takes as a standalone noun (子供こどもの頃ころ)

ごろ needs a point to blur, so it refuses a duration: 三時さんじごろ is
"about three o'clock", 三時間さんじかんごろ is nothing at all — that one is
三時間さんじかんくらい.

くらい
ごろ blurs a POINT and takes only a time word (三時さんじごろ, 来月らいげつごろ); くらい blurs an AMOUNT and takes any quantity, so 三時間さんじかんくらい hedges a span while 三時さんじくらい hedges the same point ごろ does but sounds looser and more spoken — which is why timetables and notices write 三時さんじごろ and never 三時さんじくらい.

ごとに
ごろ and ごと differ by one kana on the same host — 十日とおかごろ picks out one date and hedges it, 十日とおかごとに names a repeating ten-day interval, so reading ごろ as ごと turns a single appointment into a schedule.