Date Ranges

How to specify date ranges in get_ga4_data and how to structure period-over-period comparisons.

Valid formats

date_range_start / date_range_end accept:
  "YYYY-MM-DD"   — absolute date, e.g. "2024-01-15"
  "today"        — current day (partial — use carefully)
  "yesterday"    — last complete day
  "NdaysAgo"     — N days back from today, e.g. "7daysAgo", "30daysAgo", "90daysAgo"

NdaysAgo excludes today. 7daysAgo to yesterday = last 7 complete days.

Common windows

Period-over-period comparison

The GA4 Data API does not support multi-period in a single call. Run two separate get_ga4_data calls, then compare the results.

Example: week-over-week

Call 1 — this week:

date_range_start: "7daysAgo"
date_range_end:   "yesterday"

Call 2 — last week:

date_range_start: "14daysAgo"
date_range_end:   "8daysAgo"

Example: year-over-year for July

Call 1 — this year:

date_range_start: "2025-07-01"
date_range_end:   "2025-07-31"

Call 2 — last year:

date_range_start: "2024-07-01"
date_range_end:   "2024-07-31"

Then compute the delta: (current - prior) / prior * 100 for each metric.

Partial-day reads

today includes only the hours elapsed so far. Comparing today to yesterday is misleading — yesterday is a full day, today is partial.

For intra-day analysis, use today for both start and end and note the IST hours covered in your interpretation.

Common mistakes

• "last7days" is NOT valid — use "7daysAgo"
• "last-week" is NOT valid — use absolute dates or NdaysAgo
• Do not use date_range_end: "today" when comparing to a prior complete period
• "0daysAgo" = today (same as "today")

Load it in a session with search_skills("date-ranges"), or read the MCP resource skill://date-ranges. Markdown twin: /skills/date-ranges/index.md · Source: skills/date-ranges/SKILL.md.