I travel for work quiet a bit but, it’s very on off in nature (India / US / EU & Baltic).
For US and India there is advance notice – but it has been at two weeks once I have had a valid work visa etc.
I think most businesses understand you can’t just drop everything – and if you are felxible they can be too.
For example I push for things like ‘days in lieu’ for time a way at short notice (i.e. like a Monday / Friday to make up a long weekend – or some shorter hours the week I am back) to compensate etc.
DILs don’t cost the firm cash money, and normally if I have gone, it has saved a more seniour person going, so they are open to that type of negotiation.
Yeah – also be clear on your firm’s expenses policy before you go…..