日付と時刻

import numpy as np

# Creating datetime arrays
dates = np.array(['2024-01-01', '2024-02-01', '2024-03-01'], dtype='datetime64')
print(dates)  # ['2024-01-01' '2024-02-01' '2024-03-01']

# Date arithmetic
print(dates + np.arange(3))  # add days

# Date range
range_dates = np.arange('2024-01-01', '2024-01-10', dtype='datetime64')
print(range_dates)

# Extract components
print(dates.astype('datetime64[Y]'))  # year
print(dates.astype('datetime64[M]'))  # month

> Output: Run NumPy 2.x in your local Python environment to see the ndarray output. The Piston server does not have NumPy pre-installed — install it locally (`pip install numpy`) and compare. Actual values may vary by NumPy version and random seed.

import numpy as np

# Daily range
days = np.arange('2024-01-01', '2024-01-11', dtype='datetime64')
print("Daily:", days)

# Monthly range
months = np.arange('2024-01', '2024-07', dtype='datetime64[M]')
print("Monthly:", months)

# Hourly range
hours = np.arange('2024-01-01', '2024-01-02', dtype='datetime64[h]')
print("Hourly:", hours)

import numpy as np

start = np.array('2024-01-15', dtype='datetime64')

# Add days
print("Start:", start)
print("+7 days:", start + 7)
print("+30 days:", start + 30)
print("-5 days:", start - 5)

# Difference between dates
d1 = np.array('2024-01-01', dtype='datetime64')
d2 = np.array('2024-12-31', dtype='datetime64')
delta = d2 - d1
print("Days in 2024:", delta)

# Extract components
date = np.array('2024-07-04', dtype='datetime64')
print("Year:", date.astype('datetime64[Y]'))
print("Month:", date.astype('datetime64[M]'))

import numpy as np

start = np.datetime64('2024-01-01')
end = np.datetime64('2024-01-31')

# Count business days
bd = np.busday_count(start, end)
print(f"Business days Jan 2024: {bd}")

# Find next business day
print("Next business day after 2024-01-05:", np.busday_offset('2024-01-05', 0, roll='forward'))

# Business day range
biz_days = np.busday_offset('2024-01-01', np.arange(10))
print("First 10 business days of 2024:", biz_days)