如何将datetime信息写入netcdf4？

import netCDF4 as nc
import numpy as np
from datetime import datetime

# 创建netCDF4文件
dataset = nc.Dataset('data.nc', 'w', format='NETCDF4')

# 定义时间维度
time_dim = dataset.createDimension('time', None)
time_var = dataset.createVariable('time', np.float64, ('time',))

# 定义其他变量
data_var = dataset.createVariable('data', np.float32, ('time',))

# 生成datetime数据
start_date = datetime(2022, 1, 1)
time_data = np.array([(start_date + timedelta(days=i)).timestamp() for i in range(num_time_steps)])

# 将datetime数据写入netCDF4文件
time_var[:] = time_data

# 关闭netCDF4文件
dataset.close()