UTC+8 with no drift

The Philippines sits geographically across UTC+8 and UTC+9 (Mindanao, in the south, is east enough to be solar-close to +9), but the whole archipelago runs on one zone. Philippine Standard Time — PHT, PST, or PHST depending on which style guide you read — is UTC+8 year-round. The country has had wildly different zones historically, including a short period on UTC+8:30 in the 1940s during the Japanese occupation, but modern PHST has been stable since the 1990s.

BPO and the night shift as the main shift

Manila and Cebu are the core of the Philippine business process outsourcing industry, which primarily serves US clients. The practical result: a huge fraction of Manila's white-collar workforce works a 9pm–6am PHT shift to align with US East Coast 9am–6pm hours. Call centres, transcription services, tech support, and increasingly software engineering all run on this schedule. The "regular" daytime office, meanwhile, runs 8am–5pm for serving local and regional Asian clients.

Scheduling between Manila and the US

The Manila–New York gap is 13 hours in winter and 12 hours in summer when the US is on DST. A 9am ET call in January lands at 10pm PHT the same day, which is why "night shift" in the Philippines is really an "American day shift" offset by one calendar flip. For short ad-hoc calls with a team that isn't on the night shift, the cleanest window is 7–9pm PHT to catch US morning without killing anyone's sleep. For recurring calls, BPO teams usually just align permanently with the US counterpart's schedule and never switch back.