source dump of claude code
1import memoize from 'lodash-es/memoize.js'
2
3// This ensures you get the LOCAL date in ISO format
4export function getLocalISODate(): string {
5 // Check for ant-only date override
6 if (process.env.CLAUDE_CODE_OVERRIDE_DATE) {
7 return process.env.CLAUDE_CODE_OVERRIDE_DATE
8 }
9
10 const now = new Date()
11 const year = now.getFullYear()
12 const month = String(now.getMonth() + 1).padStart(2, '0')
13 const day = String(now.getDate()).padStart(2, '0')
14 return `${year}-${month}-${day}`
15}
16
17// Memoized for prompt-cache stability — captures the date once at session start.
18// The main interactive path gets this behavior via memoize(getUserContext) in
19// context.ts; simple mode (--bare) calls getSystemPrompt per-request and needs
20// an explicit memoized date to avoid busting the cached prefix at midnight.
21// When midnight rolls over, getDateChangeAttachments appends the new date at
22// the tail (though simple mode disables attachments, so the trade-off there is:
23// stale date after midnight vs. ~entire-conversation cache bust — stale wins).
24export const getSessionStartDate = memoize(getLocalISODate)
25
26// Returns "Month YYYY" (e.g. "February 2026") in the user's local timezone.
27// Changes monthly, not daily — used in tool prompts to minimize cache busting.
28export function getLocalMonthYear(): string {
29 const date = process.env.CLAUDE_CODE_OVERRIDE_DATE
30 ? new Date(process.env.CLAUDE_CODE_OVERRIDE_DATE)
31 : new Date()
32 return date.toLocaleString('en-US', { month: 'long', year: 'numeric' })
33}