1st January 1966 Steven
This is an advertisement for Livia’s (Cristina’s mother) hair styling, but it predates her own salon on San Marino Avenue. It makes me smile to read how “exotic” it was to have a stylist directly from Argentina that specialized in France’s latest coiffures!

It is hard to determine the date, but the phone number is presented in the old dialing format that was before area codes were invented. That sets the date somewhere before 1966 according to Wikipedia. The “AT” before the number “1-9287” would be dialed today as 626-281-9287 (with A=2 and T=8 on the dialpad).