diff --git a/retro/SKILL.md b/retro/SKILL.md
index 303c92db..25126ac3 100644
--- a/retro/SKILL.md
+++ b/retro/SKILL.md
@@ -182,7 +182,7 @@ When the user types `/retro`, run this skill.
 
 Parse the argument to determine the time window. Default to 7 days if no argument given. All times should be reported in the user's **local timezone** (use the system default — do NOT set `TZ`).
 
-**Midnight-aligned windows:** For day (`d`) and week (`w`) units, compute an absolute start date at local midnight, not a relative string. For example, if today is 2026-03-18 and the window is 7 days: the start date is 2026-03-11. Use `--since="2026-03-11"` for git log queries — git interprets a bare date as midnight in the local timezone, so this captures full calendar days regardless of what time the retro runs. For week units, multiply by 7 to get days (e.g., `2w` = 14 days back). For hour (`h`) units, use `--since="N hours ago"` since midnight alignment does not apply to sub-day windows.
+**Midnight-aligned windows:** For day (`d`) and week (`w`) units, compute an absolute start date at local midnight, not a relative string. For example, if today is 2026-03-18 and the window is 7 days: the start date is 2026-03-11. Use `--since="2026-03-11T00:00:00"` for git log queries — the explicit `T00:00:00` suffix ensures git starts from midnight. Without it, git uses the current wall-clock time (e.g., `--since="2026-03-11"` at 11pm means 11pm, not midnight). For week units, multiply by 7 to get days (e.g., `2w` = 14 days back). For hour (`h`) units, use `--since="N hours ago"` since midnight alignment does not apply to sub-day windows.
 
 **Argument validation:** If the argument doesn't match a number followed by `d`, `h`, or `w`, the word `compare`, or `compare` followed by a number and `d`/`h`/`w`, show this usage and stop:
 ```
@@ -628,8 +628,8 @@ Small, practical, realistic. Each must be something that takes <5 minutes to ado
 
 When the user runs `/retro compare` (or `/retro compare 14d`):
 
-1. Compute metrics for the current window (default 7d) using the midnight-aligned start date (same logic as the main retro — e.g., if today is 2026-03-18 and window is 7d, use `--since="2026-03-11"`)
-2. Compute metrics for the immediately prior same-length window using both `--since` and `--until` with midnight-aligned dates to avoid overlap (e.g., for a 7d window starting 2026-03-11: prior window is `--since="2026-03-04" --until="2026-03-11"`)
+1. Compute metrics for the current window (default 7d) using the midnight-aligned start date (same logic as the main retro — e.g., if today is 2026-03-18 and window is 7d, use `--since="2026-03-11T00:00:00"`)
+2. Compute metrics for the immediately prior same-length window using both `--since` and `--until` with midnight-aligned dates to avoid overlap (e.g., for a 7d window starting 2026-03-11: prior window is `--since="2026-03-04T00:00:00" --until="2026-03-11T00:00:00"`)
 3. Show a side-by-side comparison table with deltas and arrows
 4. Write a brief narrative highlighting the biggest improvements and regressions
 5. Save only the current-window snapshot to `.context/retros/` (same as a normal retro run); do **not** persist the prior-window metrics.
diff --git a/retro/SKILL.md.tmpl b/retro/SKILL.md.tmpl
index 5c6e772c..70647625 100644
--- a/retro/SKILL.md.tmpl
+++ b/retro/SKILL.md.tmpl
@@ -46,7 +46,7 @@ When the user types `/retro`, run this skill.
 
 Parse the argument to determine the time window. Default to 7 days if no argument given. All times should be reported in the user's **local timezone** (use the system default — do NOT set `TZ`).
 
-**Midnight-aligned windows:** For day (`d`) and week (`w`) units, compute an absolute start date at local midnight, not a relative string. For example, if today is 2026-03-18 and the window is 7 days: the start date is 2026-03-11. Use `--since="2026-03-11"` for git log queries — git interprets a bare date as midnight in the local timezone, so this captures full calendar days regardless of what time the retro runs. For week units, multiply by 7 to get days (e.g., `2w` = 14 days back). For hour (`h`) units, use `--since="N hours ago"` since midnight alignment does not apply to sub-day windows.
+**Midnight-aligned windows:** For day (`d`) and week (`w`) units, compute an absolute start date at local midnight, not a relative string. For example, if today is 2026-03-18 and the window is 7 days: the start date is 2026-03-11. Use `--since="2026-03-11T00:00:00"` for git log queries — the explicit `T00:00:00` suffix ensures git starts from midnight. Without it, git uses the current wall-clock time (e.g., `--since="2026-03-11"` at 11pm means 11pm, not midnight). For week units, multiply by 7 to get days (e.g., `2w` = 14 days back). For hour (`h`) units, use `--since="N hours ago"` since midnight alignment does not apply to sub-day windows.
 
 **Argument validation:** If the argument doesn't match a number followed by `d`, `h`, or `w`, the word `compare`, or `compare` followed by a number and `d`/`h`/`w`, show this usage and stop:
 ```
@@ -492,8 +492,8 @@ Small, practical, realistic. Each must be something that takes <5 minutes to ado
 
 When the user runs `/retro compare` (or `/retro compare 14d`):
 
-1. Compute metrics for the current window (default 7d) using the midnight-aligned start date (same logic as the main retro — e.g., if today is 2026-03-18 and window is 7d, use `--since="2026-03-11"`)
-2. Compute metrics for the immediately prior same-length window using both `--since` and `--until` with midnight-aligned dates to avoid overlap (e.g., for a 7d window starting 2026-03-11: prior window is `--since="2026-03-04" --until="2026-03-11"`)
+1. Compute metrics for the current window (default 7d) using the midnight-aligned start date (same logic as the main retro — e.g., if today is 2026-03-18 and window is 7d, use `--since="2026-03-11T00:00:00"`)
+2. Compute metrics for the immediately prior same-length window using both `--since` and `--until` with midnight-aligned dates to avoid overlap (e.g., for a 7d window starting 2026-03-11: prior window is `--since="2026-03-04T00:00:00" --until="2026-03-11T00:00:00"`)
 3. Show a side-by-side comparison table with deltas and arrows
 4. Write a brief narrative highlighting the biggest improvements and regressions
 5. Save only the current-window snapshot to `.context/retros/` (same as a normal retro run); do **not** persist the prior-window metrics.