Which day of the week is Pisces lucky day?

It's Thursday according to The Astrology Bible by Judy Hall.

Pisces Lucky Days

Monday. Next best - Thursday.

Each day of the week is dominated by a 'planet'. (In Astrology, the sun and moon also are 'planets'.) Monday - Moon, Tuesday - Mars, Wednesday - Mercury, Thursday - Jupiter, Friday - Venus, Saturday - Saturn, and Sunday - Sun.

Neptune is the ruler of Pisces. It's also a higher octave of the moon, hence Monday.

Jupiter is the co-ruler, hence next best being Thursday.

Incidentally, for all the signs: Aries - Tuesday, Taurus - Friday, Gemini - Wednesday, Cancer - Monday, Leo - Sunday, Virgo - Wednesday, Libra - Friday, Scorpio - Tuesday, Sagittarius - Thursday, Capricorn - Saturday, Aquarius - Wednesday then Saturday, Pisces - Monday then Thursday.

There is no such thing as "lucky days." It is determined by the planets position around the sun, and what may be a lucky Monday one week could suck the next. Instead, read your horoscope and figure out which days will be good or bad.

My sister is pisces i can say her favorite day is Sunday. She likes to sleep in the morning a lot when she is not at work

Wednesday.