Real per-day Panchang for every day of a month — powers the calendar grid. Per day: tithi (number + name), nakshatra, paksha, sunrise. In-process cached per (month, city) since it never changes.

The full-month grid is the heaviest public Panchang JSON payload (28-31 days x tithi/nakshatra/paksha/lunar-month + festival/vrat markers), so the response is gzip-negotiated via the audited _json_response_maybe_gzip helper: the DECOMPRESSED body is byte-identical to the old return out path (no contract/field/value change), and clients that do not advertise Accept-Encoding: gzip (or tiny payloads) get the unchanged JSON body. The in-process _MONTH_CACHE still stores the plain dict; the wrapper runs per request on both the cache-hit and freshly-built return paths. Each day also uses the canonical exact-key daily memo, so the Today request and this month packet share the selected day's astronomical core result instead of computing it twice.