1時頃 = 1 jikoro = around 1:00

around that time＝あの頃<ころ>anokoro／その頃<ころ>sonokoro around this time＝この頃<ころ>konokoro ※around these days＝この頃<ごろ>konogoro days around September 23＝くがつ　にじゅう　さんにちごろkugatsu nijuu sannichigoro months around September＝くがつごろkugatsugoro years around 2050＝にせん　ごじゅうねんごろnisen gojuunengoro ※About Linda's answers 1. "jikoro" should be "jigoro" 2. We(Japanese) do not say "午前一時周り = Gozen ichiji mawari ". We say 午前一時頃<ごろ> = Gozen ichijigoro .

You can also use: 午前一時周り = Gozen ichiji mawari = Around one o'clock