Timesheet Validator - Validation Rules

Business Logic:
On scheduled work days, employees are expected to work. If no time is entered and no remarks explain the absence, this indicates unapproved leave. PT employees are exempt from this rule.

Example:
Date: Jan 15 (Mon) | C/D/H: All empty → Error

Business Logic:
Differs from Rule 1 (fully empty row) — this row has some text in Col G or Col H, but none of it matches a recognised leave code. The employee wrote something but it cannot be interpreted as approved leave.

Detection uses whole-word matching (HasLeaveCode) on upCombined = UCase$(ColG & " " & ColH). Both columns are scanned together. If any exempt code is found, this rule does not fire:
• AL / SL / NPL — standard Col G dropdown leave types
• NPSL — Col H only (Others path); exempts and counted as NPL
• PUBLIC HOLIDAY — substring match (not whole-word)

Both C and D must be empty — if only one is filled, routes to Rule 2.7 instead. PT employees are exempt from this rule entirely.

Examples:
Jan 20 (Mon) | C/D: Empty, Col G: "Doctor appointment" → Error (no recognised code)
Jan 20 (Mon) | C/D: Empty, Col G: "AL (AM)" → No error ✅ (AL found → routes to Rule 2.5 (FT))
Jan 25 (Mon) | C/D: Empty, Col G: "Others", Col H: "NPSL" → No Rule 2 error ✅ (NPSL exempts, counted as NPL); Rule 16 fires

Business Logic:
If marking half-day leave (AM or PM), the employee should still work the other half and enter those hours in columns C/D. PT employees are exempt from this rule — they face Rule 2.5 (PT) instead. The (AM)/(PM) marker is read from Col G for standard leave types, and from Col H when Col G = "OTHERS".

Example:
Date: Feb 5 (Wed) | C/D: Empty, Col G: "AL (AM)" → Error

Business Logic:
PT equivalent of Rule 2.5 (FT). PT employees are exempt from Rule 2.5 (FT) (FT half-day check), but if they explicitly mark a half-day marker on a weekday with no time entries, the same data-entry error applies.

Example:
PT employee | Date: Feb 5 (Wed) | C/D: Empty, Col G: "AL (AM)" → Error

Business Logic:
Both start time (C) and end time (D) must be provided together. Having one without the other is a data entry error regardless of what leave codes are present in G/H.

Examples:
Date: Jan 20 (Mon) | C: 09:00, D: Empty, Remarks: "AL" → Error
Date: Jan 20 (Mon) | C: Empty, D: 18:00, Remarks: "" → Error

Business Logic:
PT employees are exempt from Rules 1, 2, and 2.5 (FT) (leave without reason). However, having only one of start/end time is still a data-entry error on any day type.

Example:
PT employee | Date: Jan 20 (Mon) | C: 09:00, D: Empty → Error

Business Logic:
Full-day NPL or NPSL means no work should be recorded. If C/D are filled alongside a full-day NPL/NPSL entry (without an AM/PM marker), the entry is contradictory.

Half-day NPL(AM) or NPL(PM) is valid — the employee works the other half and enters times in C/D.

Leave source rules for this check:
• Non-Others path: NPL/NPSL detected from Col G prefix (e.g. "NPL (Full Day)", "NPSL")
• Others path (Col G = "OTHERS"): only NPSL in Col H triggers this check (exact-case match). "NPL" in Col H under Others is a data-entry mistake and is not treated as full-day NPL — employees must use the Col G NPL dropdown instead.

Example (error, non-Others):
Date: Mar 4 (Tue) | C: 09:00, D: 18:00, Col G: "NPL (Full Day)" → Error

Example (error, Others path):
Date: Mar 4 (Tue) | C: 09:00, D: 18:00, Col G: "OTHERS", Col H: "NPSL" → Error

Example (valid):
Date: Mar 4 (Tue) | C: 13:00, D: 18:00, Col G: "NPL (AM)" → Half-day NPL, afternoon worked → OK

Business Logic:
If time is entered (C & D), the working hours formula (E) should calculate a numeric value. "N/A" or errors indicate formula/data issues.

Example:
Date: Jan 12 (Mon) | C: 09:00, D: 18:00, E: "N/A", actual: 9.0h → Error

Business Logic:
The working hours in column E must match the calculated difference between end time and start time [(D-C) × 24].

Example:
Date: Jan 18 (Mon) | C: 09:00, D: 18:00, E: 8.5h, actual: 9.0h → Error

Business Logic:
Employees should work their expected hours unless on approved leave. Small discrepancies within tolerance (0.5h) are allowed for rounding.

Example:
Date: Feb 8 (Mon) | actual: 7.5h, expected: 9.0h → 7.5+0.5=8.0<9.0 → Error

Business Logic:
Overtime is only permitted when actual hours exceed expected hours + tolerance. Working exactly expected hours = no OT allowed.

Example:
Date: Jan 22 (Mon) | actual: 9.0h, expected: 9.0h, OT: 1.0h → Error

Business Logic - OT buffer rule (hrOTFreeHr):
When HR column "OT free hour" = Y, employees must work >1 hour beyond expected hours before OT is counted.
• hrOTFreeHr = Y: actual - expected ≤ 1h → No OT; > 1h → OT = excess − 1
• hrOTFreeHr = N: OT = actual - expected (no buffer)

Example:
Date: Feb 3 (Wed) | actual: 11.0h, expected: 9.0h, OT(F): 2.0h, calcOT: 11-9-1=1.0h → Error

Business Logic:
5.5-day employees are expected to work Saturdays (typically 4 hours). Partial hours without a valid leave explanation require justification. Leave detection scans upCombined (Col G + Col H) — same mechanism as Rule 2.

Example:
Date: Jan 11 (Sat) | Type: 5.5-day, expected: 4.0h, actual: 2.5h, Col G: "Personal matters" → Error
Date: Jan 11 (Sat) | Type: 5.5-day, expected: 4.0h, actual: 2.5h, Col G: "AL (AM)" → OK ✅ (AL found)

Business Logic:
5.5-day staff Saturdays are working half-days. Any leave taken on a Saturday should specify AM or PM to clarify which half was taken. A warning is generated when a leave type is present but no half-day marker is found.

Example (warning):
Date: Jan 11 (Sat) | 5.5-day, Col G: "SL" → Warning: "Jan 11 - Saturday SL should specify (AM) or (PM)"

Example (valid):
Date: Jan 11 (Sat) | 5.5-day, Col G: "SL (AM)" → OK ✅

Active leave types: AL, SL, NPL only. NPSL is routed through NPL (message shows "NPL" not "NPSL").

Business Logic - Saturday OT Rule:
• First 4 hours = regular working hours
• Hours beyond 4 = overtime
• Formula: Saturday OT = actualHours - 4
• No 1-hour buffer (unlike weekday Rule 7)

Example:
Date: Jan 18 (Sat) | Type: 5.5-day, actual: 6.0h, OT(F): 2.5h, calcOT: 6.0-4.0=2.0h → Error

Business Logic - Rest day work rule:
• All hours worked on a rest day = OT (no "regular hours")
• C-D, E, and F must all match
• Applies to: Sunday, Public Holiday, AND Saturday for 5-day staff
• 5-day staff Saturday is treated as a rest day (same as Sun/PH)
• 5.5-day staff Saturday is handled separately by Rules 11 & 12

Example (Sun/PH):
Date: Jan 1 (Sun-PH) | C: 10:00, D: 15:00, E: 5.0h, F: 4.5h → Error

Example (5-day Saturday):
Date: Jan 11 (Sat) | 5-day staff | C: 10:00, D: 14:00, E: 4.0h, F: 3.5h → Error

Business Logic:
Sundays, public holidays, and Saturdays for 5-day staff are all rest days. No work = no error.
5-day staff Saturday is a rest day (same treatment as Sun/PH).

Example (Sun/PH):
Date: Jan 1 (Sun-New Year) | C/D: Empty → OK ✅ (no error)

Example (5-day Saturday):
Date: Jan 11 (Sat) | 5-day staff | C/D: Empty → OK ✅ (no error)

Business Logic:
Leave types shouldn't be marked on rest days (Sunday, Public Holiday, or Saturday for 5-day staff) since these are already non-working days.

AL / NPL on rest day: NOT counted. Warning remark + MarkError G:H.
SL on rest day: IS counted (cntSL += 0.5 or 1). Informational remark only, no MarkError. SL is counted on rest days because consecutive SL tracking spans across weekends/PH.

Example (AL):
Date: Jan 1 (Sun-New Year) | Col G: "AL" → Warning: "Jan 1 - AL marked on rest day (Sun/PH)" + MarkError

Example (SL):
Date: Jan 1 (Sun-New Year) | Col G: "SL" → Info: "Jan 1 - SL on rest day (included in consecutive SL streak)" (no MarkError, SL counted)

Why does 5-day Saturday say "(Sun/PH)" in the message?
The message template was written when this rule only covered Sunday and Public Holidays. 5-day staff Saturday was added later but the label was not updated.

Business Logic:
When Col G = "OTHERS", leave resolution switches to Col H. Only NPSL from Col H is counted (as NPL). An informational remark is always generated so HR can review what was entered in Col H.

Leave accumulation under Others:
• AL, SL, NPL (from Col G dropdown) — counted normally
• NPSL (Col H) — counted as NPL (effHasNPL = colHHasNPSL)
Example:
FT employee | Col G: "Others", Col H: "NPSL" → NPSL counted as NPL + informational remark