Yes, the date of export tax refund is 90 days, and the date of foreign exchange write-off is 180 days. In practice, you can refund the tax first and then write it off.

According to the Notice of State Taxation Administration of The People's Republic of China City, People's Republic of China (PRC) on Relevant Issues Concerning the Administration of Tax Refund (Exemption) on Export Goods (Guo Shui Fa [2004] No.64), an export enterprise shall apply to the tax refund department for tax refund (exemption) on export goods within 90 days from the date when the goods are declared for export (subject to the export date indicated in the export tax refund declaration form). If it is not handled within the time limit, it will be regarded as domestic products. Therefore, the goods exported in February should be declared as "free arrival and refund" within 90 days from the date of export.