A, B and C Shift Timings and the General Shift

A three-shift system divides the day into three 8-hour blocks. The most common Indian factory timings are A shift 06:00–14:00, B shift 14:00–22:00 and C shift 22:00–06:00. Variants include 07:00–15:00 / 15:00–23:00 / 23:00–07:00 in plants that want the morning shift to start after sunrise for commuting safety, and 08:00–16:00 / 16:00–00:00 / 00:00–08:00 in hospitals aligned to ward rounds. The C shift is the night shift for allowance and legal purposes regardless of the exact clock times.

Alongside the three shifts, most plants run a general shift (G) for office, maintenance planning, stores and management, typically 09:00–17:30 or 09:00–18:00 with a lunch break. The G shift is usually 6 days a week with Sunday off, while the A/B/C crews rotate their weekly off. Getting the G shift to overlap with the A-to-B handover at 14:00 is deliberate: supervisors and engineers are on site when both production crews are present.

Write the timings into shift templates with their own late-mark and grace rules. A 10-minute grace for A shift is different from the tolerance a night worker needs when the last bus arrives at 21:50 for a 22:00 start. Break rules also differ: the Factories Act requires at least 30 minutes of rest after 5 hours of continuous work, so an 8-hour shift usually contains a 30-minute break around the midpoint, giving 7.5 hours of work in an 8-hour spread. State the paid or unpaid status of the break in the template; it affects the hours calculation directly.

• Common timings: A 06:00–14:00, B 14:00–22:00, C 22:00–06:00
• General shift for staff functions overlaps the A-to-B handover
• Each shift template carries its own grace, late-mark and break rule
• At least 30 minutes of rest after 5 hours in factories; state if paid

The Staffing Formula: Why Three Crews Are Not Enough

Every position that must be occupied on every shift is a post: a machine operator station, a control room desk, a ward nursing station, a boiler attendant. Coverage for one post is 3 shifts × 7 days = 21 shift-slots a week. One worker with one weekly off works 6 shifts a week. So people per post = 21 ÷ 6 = 3.5. Three crews cover the three shifts on six days; the half is the weekly-off relief.

For a plant with 20 posts, that is 70 people on pattern, not 60. The extra 10 form a relief crew (sometimes called the D crew or the reliever pool) that covers weekly offs across all three shifts. On top of that, add a leave allowance: with roughly 15 to 20 days of earned, casual and sick leave per person per year plus holidays, an additional 8 to 12 percent keeps the roster from relying on overtime. 20 posts therefore realistically means 76 to 80 people.

The same arithmetic applies to hospitals, hotel front desks, fire stations and monitoring centres. Where a post runs only two shifts (a canteen 06:00–22:00), the formula is 2 × 7 ÷ 6 = 2.33 per post. Where a post runs 3 shifts on 6 days with a plant shutdown on Sunday, it is exactly 3 with no relief needed. Build the roster from these numbers before you hire; the 24/7 rota guide covers the relief pool in more depth.

• People per 24/7 post = 3 shifts × 7 days ÷ 6 working days = 3.5
• The 0.5 is the relief crew that covers weekly offs
• Add 8–12% for leave and holidays on top of the pattern
• Recalculate for posts that run fewer shifts or fewer days

Rotation: Weekly Forward, Fortnightly, or Fixed

Weekly forward rotation (A → B → C) is the norm in Indian factories: each crew works one shift for a week and moves to the later shift the next week. Moving forward (later start each week) is easier on the body clock than moving backward. A sample three-week cycle for Crew 1: Week 1 A shift, Week 2 B shift, Week 3 C shift; Crew 2 is one week behind (B, C, A); Crew 3 two weeks behind (C, A, B). Each crew takes one weekly off within the week, covered by the relief crew.

Fortnightly rotation halves the number of changeovers and is preferred where the night shift needs specialised skills that take a day to re-adjust to. Fixed shifts (permanent night crew) are used where employees choose nights for a night allowance; the Factories Act's provisions on women working at night and the OSH Code's health-check requirement for workers over 40 need extra attention there.

The rotation changeover is the risky moment. If Crew 1 finishes its last C shift at 06:00 Sunday and starts its first A shift at 06:00 Monday, the rest gap is 24 hours, which is acceptable. If a supervisor instead asks the crew to start A shift on Sunday to cover a gap, the gap is zero and the worker has done 16 hours straight. Set a rule of at least 12 hours (preferably 24) between the last shift of one rotation and the first of the next and make the roster tool or the Excel check enforce it. Patterns with fewer changeovers are compared in rotating shift schedule examples.

• Weekly forward rotation A → B → C is easiest on sleep
• Fortnightly rotation suits skill-heavy night work
• Fixed night crews need night allowance and health monitoring
• Enforce a minimum 12-hour gap at every rotation changeover

Weekly Offs and the Fourth Relief Crew

In a 24/7 plant the weekly off cannot be Sunday for everyone, so it rotates. The simplest scheme gives each worker a fixed off day within the week (Worker 1 Monday, Worker 2 Tuesday and so on), so on any given day one-sixth of each crew is off and the relief crew fills exactly those slots. The relief crew's own weekly offs fall on the day when the fewest primary workers are off, usually the day the general shift also rests.

The Factories Act (sections 52 and 53) requires one whole day of rest in every week and, where a worker is required to work on that day, a compensatory holiday within the same month or the following two months, with no more than ten consecutive days without a rest day. State Shops and Establishments Acts have similar provisions. Build the check into the roster: any worker with no O in a rolling 7-day window is a violation before anyone has worked. Full detail is in weekly off rules as per labour law, and the shift roster glossary entry covers the vocabulary.

Sample week for a 3-post unit (9 shift slots a day, 63 a week) with 10 workers plus 1 reliever: Workers 1–3 on A shift Mon–Sat with offs on Mon, Tue and Wed respectively; Workers 4–6 on B with offs Thu, Fri, Sat; Workers 7–9 on C with offs Sun, Mon, Tue; Worker 10 and the reliever fill the off slots and each take Sunday and Wednesday off. Every slot is covered and every person has one full day of rest. Lay this out in the shift schedule template in Excel and check the per-day COUNTIF totals before publishing.

• Rotate weekly offs so one-sixth of each crew is off each day
• Relief crew fills exactly the off slots; its own offs land on the quietest day
• One whole day of rest per week; comp-off if worked; max 10 days without rest
• Check every 7-day window per worker before the roster is published

Handover Overlap and Real-World Adjustments

A three-shift plant lives or dies on handover. Build 15 to 30 minutes of overlap into the roster where the process demands it: the outgoing operator briefs the incoming one on machine state, pending maintenance and quality holds. In a hospital the nursing handover at the bedside can take 30 minutes. This overlap is working time; either pay it as such or shorten the productive shift, but do not pretend it does not exist. Where budgets do not allow paid overlap, a written handover log signed by both sides is the minimum.

Real rosters get adjusted. A worker on approved leave should be replaced by the relief crew in the roster before the week starts, not discovered absent at 06:00. Swaps between workers must be approved by the shift in-charge and recorded, because an unapproved swap can put someone on two consecutive shifts or leave a skilled post covered by an unqualified person. Overtime to cover a no-show should be a supervisor's decision with the double-rate cost visible.

Hospitals add a layer: nurses need skill-mix per shift (at least one senior per ward per shift), and the roster must respect that alongside the weekly-off and rotation rules. The nurse duty roster software page and the hospital staffing guide cover that variant.

• Plan 15–30 minutes of paid overlap where handover matters
• Replace leave in the roster before publication
• Approve and record swaps; block back-to-back shifts
• Hospitals add skill-mix constraints on top of coverage

Validating Attendance Against the Roster

A roster is a plan; attendance is what happened. The two must be compared daily. For each worker, the punch-in should fall within the grace window of the assigned shift; a punch at 14:05 against an A shift (06:00–14:00) is not a late mark, it is a worker who came for the wrong shift or covered someone unrecorded. A C-shift punch-out at 06:00 belongs to the previous date's attendance. Without shift-aware validation, night crews get half-days and overtime disappears or doubles.

In Excel this means a lookup of the roster code against the attendance sheet for every worker-day and a set of IF rules for each code. It is doable for one plant and one month; it is not doable every day across three plants. Most units end up validating once at month end, by which time the disputes are two weeks old.

Attend Mitra does the comparison as punches arrive: shift templates for A, B, C and G with their own grace and break rules, a weekly roster builder with presets for forward rotation, warnings when a rostered worker has approved leave, swap requests with approval, and a live monitor showing who is present on which shift and who has not arrived. Overtime and night hours are derived from punches against the rostered shift, so the wage register shows normal and overtime hours separately, which is exactly what an inspector under the Factories Act or the Labour Codes asks to see.

• Compare each punch with the assigned shift's window, not the calendar day
• Assign C-shift punch-outs to the date the shift started
• Daily validation catches wrong-shift attendance and unrecorded covers
• Wage register must show normal and OT hours separately by shift