For applicants — Mercor, Micro1, Turing & similar AI training platforms
What “4 hours of overlap with PST” actually means — and whether you can work it from where you live
Most AI training contracts now require 4 hours of daily overlap with US Pacific time. This page walks through, region by region, what that translates to in your local hours — and where it stops being workable.
What “4 hours of overlap with PST” actually means
Mercor, Micro1, Turing, Outlier, Scale, and the other AI training platforms post contractor roles with a clause that reads almost identically across all of them: “at least 4 hours per day and minimum 20 hours per week, with overlap of 4 hours with PST”. The wording is industry-standard. It has a specific meaning that is worth being precise about before you accept a role, because the difference between the slot you negotiate and the slot you assume can be the difference between a sustainable side contract and a sleep-deprivation problem.
“PST” in these postings is shorthand for US Pacific time — generally PST (UTC−8) in winter and PDT (UTC−7) during US daylight saving from mid-March to early November. The platforms don’t usually specify which they mean. The practical reading is “Pacific time, whatever it currently is”, and you’ll want to recheck your local overlap each March and November when the US shifts.
“8am to 5pm PST” — the working day at the company headquarters in San Francisco — gives you a 9-hour window. The requirement is that 4 of your daily hours fall inside that window. You choose which 4. You don’t typically have to take the same 4 every day, but you do have to be available consistently enough that the team can plan around you, and most projects expect you to propose a slot at onboarding and then keep to it.
The requirement scales differently by tier. At 20 hours per week (the part-time tier), the 4-hour daily overlap effectively is your whole workday. At 30 or 40 hours per week, only 4 of your daily hours need to overlap PST — the rest you can do whenever suits you, before or after the overlap window. We come back to that distinction below.
Find your overlap
Pick the city or region nearest you to see when PST 8am–5pm falls in your local time, and which 4-hour slot is the most humane to work.
The world view
A quick picture of overlap difficulty by region. Country shading represents the most populated time zone within that country — large countries like the US, Canada, Russia, Brazil, and Australia span multiple zones, and the picture varies inside their borders.
Overlap difficulty with PST 8am–5pm by region
Hover a country to see its tier.
Where the overlap window lands locally
For each region, the colored band shows the full 9-hour PST overlap window in local time — pick any 4 contiguous hours of it. Color shows how humane each hour is locally. Green is daytime (8am–6pm); amber is early morning or evening; red is the 10pm–6am sleep zone.
Region by region
What the working day actually looks like, by where you live.
Americas (US, Canada, LATAM)
Overlap falls during normal working hours.
From the West Coast, the entire 9-hour window is your normal day — there is nothing to negotiate. From the East Coast, PST 8am–5pm corresponds to 11am–8pm local; you have a long afternoon overlap that runs slightly into the evening, and the earliest 4-hour slice (11am–3pm EST) keeps you home for dinner. From Mexico, Central America, and the bulk of Spanish-speaking South America, the overlap is similarly daytime-friendly. Brazil sits at the edge — PST 8am–5pm becomes 1pm–10pm BRT, so an early-end slot like 1–5pm is comfortable while a late slot reaches 10pm.
This is the easy case. The 30 and 40 hour-per-week tiers are equally workable because your additional flexible hours sit in the morning, before the overlap.
UK, Ireland, Western Europe
Afternoon and evening shift; manageable.
From the UK, the overlap window runs from 4pm to 1am local. The earliest 4-hour slice (4pm–8pm GMT) is the sweet spot for most people — you keep your morning entirely free, and finish in time for an evening meal. The latest viable slice (9pm–1am GMT) extends into late evening but is still tolerable as a regular schedule for many night-leaning people. Western Europe (France, Germany, Spain, Italy, the Netherlands, Poland) sits one hour later: 5pm–9pm CET as the early slice, 10pm–2am CET as the late slice. Helsinki, Athens, and the Baltic states sit one hour later again.
The 30 and 40-hour-per-week tiers work well from this region because the flexible hours can be done in the morning UK time, before the PST overlap begins. A typical 40hr/week pattern from London is 11am–3pm GMT (flexible morning work) plus 4pm–8pm GMT (PST overlap) — roughly mirroring a UK office day.
Eastern Europe, Middle East, Russia, Africa
Evening to late-evening shift; demanding but feasible.
From Bucharest, Cairo, Tel Aviv, or Istanbul (UTC+2 to +3), the overlap is 6pm–3am local. The earliest 4-hour slice ends at 10pm — late but still pre-sleep. From Moscow, Riyadh, and East Africa (UTC+3), it is 7pm–4am, where the early slice ends at 11pm. From the Gulf (UAE at UTC+4), the overlap is 8pm–5am, and even the earliest 4-hour slot (8pm–12am) finishes at midnight.
This is the region where slot choice matters most. Picking the early end of the 9-hour window is the difference between a long-evening shift and an overnight one. Most contractors who sustain this region long-term run the early slice consistently and protect their morning sleep.
South Asia (India, Pakistan, Bangladesh)
Predominantly overnight; reverse-shift required.
From India, PST 8am–5pm is 9:30pm–6:30am IST. Even the most generous 4-hour slice (9:30pm–1:30am IST) runs through midnight and into the early hours. From Pakistan it is 9pm–6am; from Bangladesh, 10pm–7am. There is no slot in this region that sits inside normal sleep hours.
India-based contractors on these platforms generally run a fully reverse-shifted lifestyle: sleep 6am–2pm, work 9pm–1am or thereabouts on the platform, with 30 or 40-hour-per-week flexible hours done in the late afternoon and evening. It is workable — many people do it — but it is not a small lifestyle adjustment, and the platforms are aware of this. Mercor’s pay periods are calculated in IST regardless of where you live, which is one of the few concessions to the South Asian workforce.
East Asia, SE Asia, Oceania
Pre-dawn shift; only viable if you genuinely accept it.
This is the most demanding region. From Singapore and Beijing (UTC+8), PST 8am–5pm is midnight–9am. From Tokyo and Seoul (UTC+9), 1am–10am. From Sydney (UTC+10), 2am–11am. From Auckland (UTC+12), 4am–1pm. The window curves back toward daytime as you move east, which means New Zealand actually has a daytime-ending overlap (the 8am–1pm portion of the local day) — but you have to start work at 4am to access it.
The honest framing for this region is: only take the role if you have already done shift work successfully and know what early-morning starts do to you. Most contractors in this region pick the latest available PST slice (PST 1pm–5pm = local 5am–9am from Tokyo, 6am–10am from Sydney) so the overlap at least ends in their normal morning. The 30 or 40-hour tiers help here, because you can do flexible hours in the late afternoon — your normal day — and front-load the overlap into your dawn.
20 vs 30 vs 40 hours per week
The 4-hour daily overlap is fixed across all three tiers. What changes is what happens to the rest of your contracted hours.
20 hr/wk
Part-time
4 hours × 5 days. The overlap is your workday. There are no additional flexible hours to schedule.
Best for: clinicians and professionals fitting AI training around a primary role; people testing whether the work suits them before committing more.
30 hr/wk
Three-quarter time
4 hours overlap + 2 flexible hours, daily. The flexible 2 hours can sit before or after your overlap window.
Best for: people who want substantial income but want to keep mornings (or post-overlap evenings) free for other commitments.
40 hr/wk
Full-time
4 hours overlap + 4 flexible hours, daily. From a UK perspective this looks like an 11am–8pm working day, but the morning half is flexible and the afternoon half is fixed.
Best for: people whose AI training contract is their primary income, or who want to maximise total earnings.
A common pattern from outside the Americas is to combine the overlap window with a separate flexible block earlier in the day. From the UK at 40 hrs/week: morning emails and async work 9am–1pm GMT, lunch, then PST overlap 4pm–8pm GMT. From India at 30 hrs/week: late afternoon flexible work 4pm–6pm IST, evening break, then PST overlap 9:30pm–1:30am IST. The shape of your day depends as much on the flexible hours as the overlap.
Daylight saving — the gotcha
The contracts say “PST” but the platforms enforce “Pacific time”, which moves twice a year. From mid-March to early November, the US shifts to PDT (UTC−7), which means the 8am–5pm window in San Francisco translates to one hour earlier in your local time. A 4–8pm GMT slot in winter becomes 3–7pm GMT in summer (the UK switches at the same time, partly compensating; Asia and most of Africa do not, so the change is starker for them).
If your country observes daylight saving on a different schedule from the US, expect two awkward weeks each year — the second week of March and the first week of November — when the overlap is offset by an additional hour during the gap between the two countries’ transitions. The platforms don’t usually adjust their guidance for this, so plan your time around the transition manually.
The practical implication for negotiating your slot: pick a slot that works in both winter and summer. If your winter slot is 4–8pm and you cannot manage 3–7pm in summer because of an existing afternoon commitment, you will need to renegotiate twice a year.
If you are a clinician considering this work
Most of this page applies regardless of profession. Two additional considerations come up specifically for clinicians considering remote AI training work alongside an existing role.
The first is shift overlap. From the UK, the most humane PST overlap (4–8pm GMT) collides directly with most evening clinical commitments — late shifts, on-call rotas, evening surgeries, GP urgent-care sessions. If your clinical work is daytime-only, the AI training overlap fits cleanly around it on non-clinical days. If you do evenings clinically, you’ll need to pick AI training shifts on rota days off, leave days, or as a dedicated non-clinical day each week.
The second is the 20-hour minimum. The overlap is a daily requirement, but the weekly hours total is the binding contract. Twenty hours per week, sustained, requires you to find a consistent slot most weekdays — not impossible alongside three or four clinical days a week, but it does need planning. Clinicians who treat this as ad-hoc evening work tend to fall short of the weekly minimum and lose the contract.
If you are a clinician and want to think through whether this kind of work suits you more broadly — task style, feedback culture, scope risk, scoring opacity — we have a separate decision guide:
Frequently asked questions
What does “4 hours of overlap with PST” actually mean?
It means 4 of your daily working hours must fall inside the 9-hour window of 8am–5pm Pacific time. You choose which 4. The other hours of your contracted total can be worked whenever suits you, subject to your specific contract.
Does “PST” mean PST or PDT?
Job postings write “PST” but in practice mean Pacific time, which is PST (UTC−8) in winter and PDT (UTC−7) during US daylight saving (mid-March to early November). The clock you need to overlap with shifts twice a year. If your country also observes daylight saving on a different schedule, your local overlap hours will move slightly during transition weeks.
Can I split the 4 hours into two blocks?
This depends on the specific contract and project, but the typical expectation is contiguous hours. The overlap is meant to enable real-time collaboration — message replies, code reviews, calls — not just attendance. Splitting into two short blocks defeats that purpose, and most project leads will push back. If you genuinely need to split, raise it before accepting the role.
Which 4 hours of the 9-hour PST window do I have to choose?
Any contiguous 4 hours within 8am–5pm PST — earliest is 8am–12pm PST, latest is 1pm–5pm PST. Most projects let you propose your own slot at onboarding, then expect you to keep to it. Pick the slot that aligns best with your local sleep schedule and existing commitments.
How does the 20, 30, or 40 hour-per-week tier change my schedule?
The 4-hour daily overlap requirement is the same across tiers. What changes is what happens to the rest of your time. At 20 hrs/week (4 hrs × 5 days), the overlap is your entire workday. At 30 hrs/week, you have an additional 2 hours per day to schedule whenever suits you. At 40 hrs/week, you have 4 additional flexible hours per day. The flexible hours can sit before or after your overlap window — for someone in the UK choosing a 4–8pm overlap, the flexible 30/40-hour hours might be done in the morning before.
Can I do this from the UK without working through the night?
Yes. From the UK, the earliest 4-hour overlap slot is 4pm–8pm GMT (matching PST 8am–12pm). That keeps you entirely out of sleep hours. The latest viable slot is 9pm–1am GMT, which crosses into late evening but is still tolerable for many people. During US daylight saving, both slots shift one hour earlier in UK terms. The UK is among the most humane regions for this kind of contract.
Is it possible to do this from India without flipping my sleep schedule?
Realistically, no. From India, the PST 8am–5pm window translates to 9:30pm–6:30am IST. Even the most generous 4-hour slice (9:30pm–1:30am IST) ends in the early morning and competes directly with sleep. Most India-based contractors on these platforms run a reverse-shift lifestyle — sleeping in the morning, working evening into early hours. It is done routinely but it is a significant lifestyle change, not a tweak.
Does Mercor or Micro1 actually monitor whether I’m online during my overlap hours?
Mercor uses a desktop time-tracking tool called Insightful for most projects, which logs working hours and takes periodic screenshots. Hours are calculated on a strict pay-period basis (Mercor uses IST pay periods regardless of where you are based). Project leads also see your activity timing relative to the overlap window, so consistent absence during stated overlap hours is visible. Micro1 and other platforms have similar mechanisms. The overlap is not just a self-declaration.
What if my country doesn’t observe daylight saving while the US does?
Your local overlap window will shift by an hour twice a year. For example, India does not observe DST. When the US is on PDT (UTC−7) from mid-March to early November, the PST 8am–5pm window translates to 8:30pm–5:30am IST instead of the winter 9:30pm–6:30am IST. If you negotiated a 9:30pm–1:30am slot in winter, in summer that becomes 8:30pm–12:30am — slightly more humane. Plan for the shift; it does not happen automatically on the platform side.
I am a UK-based clinician — can I do this around NHS or locum shifts?
If your overlap is 4–8pm or 5–9pm UK time, that conflicts directly with most evening clinical commitments — the late shift, on-call, evening surgeries. If you only do daytime clinical work, the overlap is workable on non-clinical days. Most clinicians who combine the two run AI training work on rota days off, leave days, or as a non-clinical day each week. The 20-hour minimum requires you to find that block consistently, which is the binding constraint, not the overlap itself.